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COST<br />

(European Cooperation in Science and Technology)<br />

UNIVERSITA’ DEGLI STUDI MEDITERRANEA<br />

DI REGGIO CALABRIA<br />

Facoltà di Ingegneria<br />

Short Term Scientific Mission – ITALY<br />

Manchester <strong>BHLS</strong><br />

<strong>RESEARCH</strong> <strong>APPROACH</strong> <strong>ABOUT</strong><br />

<strong>RELIABILITY</strong> <strong>OF</strong> <strong>BHLS</strong><br />

COST research project<br />

(Action TU 0603 - Buses with a high level of service)<br />

Professor:<br />

Domenico Gattuso<br />

Student:<br />

Salvatore Napoli


INTRODUCTION<br />

pag.3<br />

CHAPTER I – REASEARCH <strong>APPROACH</strong><br />

1.1. Introduction pag.4<br />

1.2. State of the performance indicators systems for Public Transport pag. 4<br />

1.3. General approach to the evaluation of performance indicators pag.5<br />

1.4. Approach to the analysis of reliability parameters pag.8<br />

1.4.1. Definition of reliability pag.9<br />

1.4.2. Components of public transport reliability pag.1<br />

1.4.3. Reliability measurement methods and monitoring processes<br />

proposed by some literature studies<br />

CHAPTER II –<br />

PROPOSED <strong>APPROACH</strong> TO EVALUATE<br />

<strong>RELIABILITY</strong> ON PUBLIC TRANSPORT SERVICES<br />

0<br />

pag.1<br />

2.1. Definition of reliability pag.1<br />

8<br />

2.2. Defining the type of service pag.1<br />

9<br />

2.3. Approaches for estimating the value of reliability pag.1<br />

9<br />

2.3.1. Run based services pag.1<br />

9<br />

2.3.2. Frequency based services pag.2<br />

CHAPTER III – ORGANIZATION AND EXECUTIONS <strong>OF</strong> THE<br />

<strong>RELIABILITY</strong> ANALYSIS ON THE FIELD<br />

1<br />

1<br />

3.1. Operations on site : Characteristics of the analyzed line pag.2<br />

3<br />

3.2. Collected Data pag.2<br />

8<br />

3.3. Reliability Indicators Valuation pag.3<br />

8<br />

3.4. Overview and conclusions pag.4<br />

3<br />

Bibliography<br />

pag.4<br />

4<br />

| Short term Scientific Mission -ITALY 2


INTRODUCTION<br />

The research for the Short Term Scientific Mission in COST (Action TU 0603 - Buses<br />

with a High Level of Service), supported by European Community, achieves two specific<br />

goals:<br />

- analysis of a “Bus High Level Service” for an European city (Manchester);<br />

- analysis of performances of a <strong>BHLS</strong> line in Manchester, and in particular reliability<br />

of <strong>BHLS</strong> service.<br />

The first phase of research includes a literature analysis which tries to identify the technical<br />

features concerning <strong>BHLS</strong> transport systems. The second phase is characterized by on site<br />

analysis through the utilization of a Template provided by COST and through several<br />

meetings with the company management. During this phase it was very important to meet<br />

the management that organizes the transport system (GMPTE), to obtain information about<br />

vehicles and line features, and future developments.<br />

After the collected Data Base valuation, the third and last phase was developed which<br />

consists of an analysis of the reliability of a specific line. There were descriptions about the<br />

line and its critical points, focusing the attention on the valuation of several reliability<br />

indicators in concordance with the data collected during the short mission.<br />

| Short term Scientific Mission -ITALY 3


CHAPTER I – <strong>RESEARCH</strong> <strong>APPROACH</strong><br />

1.1. Introduction<br />

As in the productive field, in which there are many regulations on quality, it was also<br />

necessary to introduce the same regulations to the services field because of their different<br />

backgrounds.<br />

Many different users and community requirements must be satisfied because of the<br />

important role that the transport field has in our society, the complexity of its features, the<br />

strong demand to improve the level of service and efficiency production, and the need to<br />

respect the environment.<br />

The basic concepts such as the system view, the process management, the continuous<br />

improvement, customer satisfaction and all contents that are reported by ISO9000 standard<br />

and Total Quality Management, represent the reference for all the organizations that decide<br />

to direct their management according to the principles of quality.<br />

Every transport company must analyze the characteristics of realized service and define a<br />

set of standards, through efficiency and effectiveness factors of the system; these are<br />

obtained through the analysis of performances offered to the customers and continuously<br />

monitored and updated.<br />

There are different studies in literature that analyze these factors and provide indicators<br />

and approaches to the quantitative measure; the most important indicators are the<br />

following, focusing on the reliability indicators.<br />

1.2 State of the performance indicators systems for Public Transport<br />

The evaluation of the performances of a public transport system is a complex problem due<br />

to the straight co-relation among the different objectives pursued by different stakeholders<br />

to express an opinion (service provider, customers, community).<br />

According to the service provider, namely the operator of public transport system, its main<br />

interest is to produce the service in a way to satisfy the demand, compatibly respecting the<br />

resources constraint. Users who represent those who are using the public service would<br />

like to obtain the service as cheap as possible, but also have it be reliable and with a good<br />

| Short term Scientific Mission -ITALY 4


level in quality and safety.<br />

Each social component (service provider, users and community) has different needs and<br />

therefore its own perception about the performances of the public transport system. The<br />

service provider, according to a far-sighted business, also considers the customer and<br />

community needs.<br />

Usually, the public transport evaluations are developed to check the differences between<br />

actual and past performances, obtaining a comprised evaluation during the time. The<br />

evaluation can also be used to provide a benchmark with another company, or as the best<br />

term of comparison. Obviously, the comparison needs to be founded on shared and<br />

uniquely determined parameters.<br />

In the field of specialized literature (Coelli et al., 1998; Russo and Varipapa, 2000;<br />

Cantarella and Di Gangi, 2002), methods to analyze performances of public transport<br />

companies are classified in two different types:<br />

• parameters methods;<br />

• non- parameters methods.<br />

Actually, to analyze the performances of a public transport company the indicators<br />

analysis is used, but there are also other methods like stochastic frontiers, econometric<br />

models of production, and Data Envelopment Analysis whose parameters need to be<br />

calibrated; further more these methods are being developed.<br />

Between the indicators based methods it’s possible to distinguish two approaches: the first<br />

assumes that just one indicator is enough to evaluate the system performances (Hensher,<br />

1992; Obeng et al., 1992; Oum and Yu, 1995; Preston, 1995; Tretheway and Waters II,<br />

1995). On the other hand, the second approach is based on the research of a set of<br />

indicators to provide an analytical approach to analyze the system (OCSE, 1980; Miller et<br />

al., 1984; Fielding et. al., 1985; MacDorman, 1988; Gattuso, 1992; Di Gangi and Montella,<br />

1995; CERTU, 1997; Gattuso et al., 2002). This work focuses attention on the second<br />

approach provided before and on the evaluation methods of indicators about<br />

reliability/regularity/punctuality that are linked to both a service provider and users.<br />

1.3 General approach to the evaluation of performance indicators<br />

| Short term Scientific Mission -ITALY 5


The set of indicators approach, developed by different authors, (Fielding et al., 1985)<br />

focuses attention on the public transport system performances evaluations according to the<br />

service provider perspective.<br />

Any uniform set of transit performance indicators must be constructed with due regard to<br />

both their intended use, and to the limitations of available data. Although transit operators<br />

are apprehensive about the use of performance indicators, they should appreciate the<br />

benefits. Performance indicators provide an opportunity to elevate the general<br />

understanding of transit's capabilities and costs by emphasizing the productive use of<br />

capital and labor, rather than focusing performance only on ridership and operating costs.<br />

According to Fielding et al. during the evaluation it’s important to refer to two types of<br />

indicators:<br />

efficiency indicators, that measure the relationship between the input used in the<br />

system productive process and the output used in the service provided;<br />

effectiveness indicators, that measure the system capability to pursue a determinate<br />

objective.<br />

In the proposed conceptual model (see Fig. 1.1), the individuation of effectiveness and<br />

efficiency indicators is linked with the knowledge of data about:<br />

service inputs (workforce, capital, energy);<br />

service outputs, (vehicles-hour, vehicles-km, seats-km);<br />

utilization of service provided (passengers, passengers-km, revenues).<br />

SERVICE<br />

INPUTS<br />

Workers<br />

Capital<br />

Energy<br />

Cost efficiency<br />

Cost Effectiveness<br />

SERVICE<br />

OUTPUTS<br />

Vehicles-hour<br />

Vehicles-Km<br />

Capacity-Km<br />

Service Effectiveness<br />

UTILIZED<br />

SERVICE<br />

Passengers<br />

Passengers-Km<br />

Profits<br />

| Short term Scientific Mission -ITALY 6


Fig. 1.1 – Conceptual model of Fielding et al. (1985)<br />

An opportune ratio between output and input measures, allow to define the costs efficiency<br />

indicators (work efficiency, vehicles efficiency, efficiency in fuel consumption, efficiency<br />

of maintenance, output per unit of cost). An opportune ratio between output and input<br />

measures, allow to define the costs efficiency indicators (work efficiency, vehicles<br />

efficiency, efficiency in fuel consumption, efficiency of maintenance, output per unit of<br />

cost).<br />

The effectiveness costs indicators are derived by the ratio between utilized service and<br />

input measures ( utilized service per unit of cost, revenues production per unit of cost).<br />

Finally, with the ratio between utilized service and output measures, it’s possible to obtain<br />

the service effectiveness indicators (service utilized, operative safety, revenues production,<br />

public economic support).<br />

One evolution of the conceptual scheme is provided by Gattuso (Gattuso, 1992), according<br />

to whom evaluates the public transport system performances, the service provider has to<br />

quantify three different aspects:<br />

- system productivity;<br />

- users satisfaction level (effectiveness);<br />

- regularity and reliability of the services.<br />

The first aspect is estimated through the classic parameters of efficiency (the efficiency<br />

describes the relations between provided output and resources used for the production).<br />

The level of satisfaction of users request can be obtained through parameters of<br />

effectiveness and of utilization of the service provided.<br />

Finally, it is important to underline the difference between regularity and the reliability of<br />

the service; regularity checks the differences between the provided service and the<br />

scheduled service (e.g. time of runs), while reliability considers the probability that the<br />

system can have a crisis (e.g. failures and accidents). The definition of parameters above<br />

(Fig.1.2) is linked to the relations among the different types of measures:<br />

- company’s resources;<br />

| Short term Scientific Mission -ITALY 7


- provided service;<br />

- scheduled service;<br />

- utilized service.<br />

Fig.1.2- Scheme of the relations among service provider interest<br />

1.4 Approach to the analysis of reliability parameters<br />

The mobility problems and in particular, the cities' congestion are tightly linked with the<br />

modal disequilibrium choosing the means of transportation. In fact, private cars are chosen<br />

over public transport service.<br />

The users' choice, for short trips in the urban context, is influenced mostly by the time<br />

attribute. For this reason the public transport company commitment is not only to try to<br />

respect the travel time and the adherence between scheduled time and real time, but also to<br />

try to reduce the waiting time at the stops and to guarantee more information to the<br />

passengers.<br />

It’s easy to understand the need to adopt opportune parameters that allow the analysis of<br />

the system and the individuation of problems to fix in order to obtain a service that can be<br />

defined as “reliable” from the users.<br />

| Short term Scientific Mission -ITALY 8


1.4.1. Definition of reliability<br />

There are different definitions of reliability, particularly within transport, and different<br />

modes have different sources of reliability which relate to uncertainty within individual<br />

aspects of their journey.<br />

The term ‘reliability’ within a transport context relates to an uncertainty in the time taken<br />

to travel from the start to the end of a person’s journey. This uncertainty means that a<br />

person must make some allowance in the timing of their journey to adjust for this<br />

uncertainty so that they can still reach the end within a desirable time span. Reliability is<br />

important for operators and passengers alike. For operators, unreliable services cause<br />

difficulties in timetabling and resource planning. Also, unreliable services are typically<br />

loaded more unevenly, causing issues of passenger overloading and possible breaching of<br />

loading licenses.<br />

Valuations of reliability can be estimated using revealed and stated preference data.<br />

However, most valuations are undertaken using stated preference techniques, where a<br />

survey asks respondents about hypothetical situations. From these situations, values can be<br />

determined for changes in average delay and the variation in delay (which are both service<br />

characteristics), or by using more complex scheduling models that focus more on<br />

passenger travel information.<br />

The concepts of reliability can be divided into departure time, (punctuality and variability<br />

around expected departure time), travel time (variability around expected travel time) and<br />

arrival time (punctuality and variability around expected arrival time).<br />

Besides the various new activities around the reliability of transport systems, there is an<br />

OECD working group preparing a report on the “Surface Transport Networks: Improving<br />

Reliability and Levels of Service”. This report will be edited in September 2009 (JTRC,<br />

2009).<br />

The transport reliability literature review, done by the OECD working group reveals a<br />

number of ways in which transport reliability can be defined. A useful definition<br />

recognizes that network users time their actions according to expected network<br />

performance. That’s why the OECD defined reliability as “The ability of the transport<br />

| Short term Scientific Mission -ITALY 9


system to provide the expected level of service quality, on which users have organized<br />

their activities”. According to this definition, reliability can be improved either by<br />

supplying better reliability or by changing expectations of the level of reliability.<br />

1.4.2 Components of public transport reliability<br />

The most important components of public transport reliability are the following:<br />

• punctuality, is defined as adherence to schedule and is measured through the mean<br />

delay percentage outside of comfort zone ( e.g. un minute – early to 5 minute late);<br />

• cancellations, are defined as whether scheduled bus actually arrives; cancellation<br />

can happen at the departure or during the trip. Can be measured by mean delay.<br />

• variability, around expected time, it’s usually measured using standard deviation<br />

Tab.1.1 - Notion of public transport reliability (Vincent, 2008)<br />

Term Definition Standard measures<br />

Punctuality<br />

Adherence to schedule<br />

Mean delay<br />

• departure<br />

Percentage outside of “comfort<br />

• arrival<br />

zone”(e.g.1min-erlay to 5 min late)<br />

Cancellations<br />

• at departure<br />

• during trip<br />

Variability around expected<br />

• departure time<br />

• travel time<br />

• arrival time<br />

Whether a scheduled train or bus<br />

actually arrives<br />

Spread around “expected x time”<br />

Note: “expected x time” can be:<br />

• average time;<br />

• targeted time (e.g.<br />

scheduled time)<br />

Mean delay (which is a function of<br />

headway)<br />

Standard deviation<br />

Waiting time variability Spread around average waiting time Standard deviation<br />

*The UK rail industry uses “reliability” to refer to the term described here as “cancellations”<br />

The interpretation of variability depends crucially on the meaning assigned to the term<br />

‘expected value’. For example, consider a bus that is always late relative to schedule, by x<br />

minutes:<br />

if ‘expected value’ is based on the bus schedule then the bus is exhibiting<br />

variability;<br />

if ‘expected value’ is based on the expectations of a passenger not familiar with the<br />

bus then the bus is exhibiting variability;<br />

| Short term Scientific Mission -ITALY 10


ut if ‘expected value’ is based on observed lateness over the past few months then<br />

the bus would be exhibiting no variability.<br />

In general, throughout the literature, sources agree that variability should refer to the<br />

unpredictable component of variability, i.e. the component of variability that remains after<br />

predictable variations (e.g. longer trip times during peak hours) are removed.<br />

The concepts of reliability can be further broken down into departure time, travel time and<br />

arrival time, as shown in Table 1.2.<br />

Components<br />

Departure time<br />

Travel time<br />

Arrival time<br />

Tab.1.2 - Concepts of reliability ( Vincent, 2008)<br />

Subcategories<br />

Punctuality<br />

Variability around expected departure time<br />

Variability around expected travel time<br />

Punctuality<br />

Variability around expected arrival time<br />

Note: departure time punctuality + travel time variability= arrival time punctuality<br />

Most studies of reliability focus on either travel time variability or arrival time variability.<br />

Only a few studies direct attention to waiting time variability.<br />

The relationship between travel time variability and arrival time variability is worth noting.<br />

If departure time is certain (as is presumed in a number of studies) then travel time<br />

variability is equivalent to arrival time variability. In such studies, a researcher can focus<br />

on either travel time variability or arrival time variability.<br />

1.4.3 Reliability measurement methods and monitoring processes proposed by some<br />

literature studies<br />

The study of “Land Transport New Zealand Research Report” (Vincent, 2008) about<br />

Measurement Valuation of Public Transport Reliability provides an overview of the<br />

concept of reliability, particularly the impact that service reliability has on passengers and<br />

operators. The ‘reliability’ within a transport context relates to an uncertainty in the time<br />

taken to travel from the start to the end of a person’s journey.<br />

A reliability valuation approach is applied to a New Zealand context. Finally, the<br />

implications of the approach for planning are outlined.<br />

| Short term Scientific Mission -ITALY 11


Three main measures are used for valuing reliability:<br />

- value of delay minutes (average minutes’ lateness);<br />

- reliability ratio (variance approach);<br />

- scheduling costs.<br />

The main approaches to estimate the value of reliability are functions of delay. The<br />

following are some of the available models:<br />

<br />

The mean delay approach, incorporates either delays or expected delays into the<br />

estimated utility function. The approach focuses on delays relative to schedule and<br />

therefore is only applicable to public transport. The model equation is::<br />

Utility = T + λ E(DM)<br />

where T = scheduled travel time; E(DM) = expected delay minutes after schedule;<br />

λ= model parameter.<br />

<br />

The variance delay approach attempts to value variability in travel times explicitly<br />

by incorporating it into an estimated utility function. The main measures of<br />

variability used are standard deviations and coefficients of variation. The variance<br />

delay approach is commonly applied, perhaps because it is relatively easy to<br />

implement and it produces reliability ratios.<br />

The reliability ratio is commonly associated with studies where respondents are<br />

presented with representative trips in a stated preference format. To calculate the<br />

reliability ratio, researchers estimate a utility function and then divide the<br />

coefficient on the standard deviation of travel time (generally) by the coefficient of<br />

travel time. The reliability ratio can be easily used to value improvements in<br />

transport reliability. The model equation is:<br />

Utility = T + λ f(S)<br />

where T = scheduled travel time; f(S) = Standard Deviation (SD) or coefficient of<br />

variation of travel time; λ = model parameter.<br />

<br />

The scheduling cost approach directs attention away from actual variability and<br />

towards the costs of variability, i.e. the costs associated with being early or late.<br />

The scheduling cost approach presents respondents with a Preferred Arrival Time<br />

(PAT) (e.g. a time when they want to be at their destination) and gives them a<br />

| Short term Scientific Mission -ITALY 12


choice of alternatives. Each alternative has different implications for the<br />

respondent’s arrival relative to their preferred arrival time. The scheduling cost<br />

approach uses their responses to infer the cost associated with being early or late to<br />

the destination. The scheduling cost approach is often preferred in academic studies<br />

because it has strong theoretical grounds and perhaps because it focuses on the<br />

main reasons why travelers value reliability: they want to get to work on time<br />

without leaving home too early. The model equation is:<br />

Utility = αE(T) + βE(SDE) + γE(SDL) + θP<br />

where E(T) = expected travel time; E(SDE) = expected time before Preferred<br />

Arrival Time (PAT); E(SDL) = expected time after PAT; P = probability of arriving<br />

after PAT; β, γ, θ = model parameters.<br />

For passengers, unreliable services cause adjustments in an individual’s desired trip<br />

making behavior to account for the possibility of a service not operating ‘as normal’:<br />

Arrival time variability causes the public transport user to arrive at their destination<br />

late and/or forces the traveler to take an earlier service. Arrival time variability can<br />

also cause the traveler to arrive at their destination too early.<br />

Departure time variability has the following costs for public transport users:<br />

• increased waiting times for the traveler. Late services cause travelers to have<br />

to wait some time after arriving at their stop or station. Early services also<br />

increase waiting times because they force the traveler to wait for the next<br />

service;<br />

• increased concern and anxiety caused purely by uncertainty about when the<br />

next service will arrive.<br />

In-vehicle-time (IVT) variability has the following costs for public transport users:<br />

• increased anxiety caused by fears of arriving late at the destination;<br />

• increased anxiety caused by uncertainty about how long they will have to<br />

spend in the service.<br />

The relationship between travel time variability and arrival time variability is worth noting.<br />

If departure time is certain (as is presumed in a number of studies) then travel time<br />

variability is equivalent to arrival time variability. In such studies, a researcher can focus<br />

on either travel time variability or arrival time variability.<br />

| Short term Scientific Mission -ITALY 13


.<br />

The study “The (in)efficiency of trams and buses in Brussels: a fine geographical<br />

analysis”, proposed by Courtois and Dobruszkes (2008), analyzes the geography of traffic<br />

conditions affecting the trams and buses of Brussels’ main mass transit network; the goal<br />

of this study is the valuation of three indicators:<br />

• commercial speed;<br />

• irregularity;<br />

• lost time.<br />

This analysis is based fundamentally on the data that STIB/MIVB collects through its<br />

Operating Aid System (OAS); this system must be able to follow the vehicles’ progress in<br />

real time and take action if problem arose. The approach involved two inputs are as<br />

follows:<br />

the raw data were extracted from the OAS (segment by segment, line by line, in first<br />

one and then the other direction) and pre-processed to be regrouped by 15, 30 or 60<br />

minute periods, and then they were regrouped in a single database;<br />

Then digitizing the STIB/MIVB network completely and assigning the STIB/MIVB’s<br />

standard code to each segment (geocoding) enabled to connect the data with their<br />

segments for mapping and analysis.<br />

The data that they used refer to all the segments between stops that were covered by the<br />

operator’s trams and buses during the week from 6 a.m. to 11 p.m. for one month (this<br />

period was sufficiently extensive to avoid atypical situations). In addition, they excluded<br />

the 5% of extreme travel times (minima and maxima) that often correspond to unusual<br />

situations (vehicle break-downs, driver absent or late when s/he theoretically should have<br />

clocked in, one-off work done at the start or end of the day, and so on).<br />

This study added to the classical measurement of commercial speed that of irregularity of<br />

service and time lost by the vehicles; these three indicators would give complementary<br />

information about the network’s performances on the segment level.<br />

The analysis underlines how great the variations in commercial speed and irregularity of<br />

service are in the course of a day. It is possible to see a parallel between the drop in<br />

commercial speed and increase in irregularity, which complicates the operator’s job even<br />

more.<br />

| Short term Scientific Mission -ITALY 14


Analysis of commercial speed<br />

Commercial speed gives an idea of the network’s performance through the speed at what a<br />

trip may be made. For the passenger, it contributes to the total time of her/his trip. For the<br />

operator, the commercial speed has a direct impact on the number of vehicles to put on line<br />

to the extent that this figure is directly linked to the route travel time and frequency of<br />

service. The analysis underlines the tram and the bus line segments’ rankings by<br />

commercial speed. It is possible to see the segments that are covered at very low<br />

commercial speeds.<br />

Analysis of irregularity over a given period<br />

The segment travel times vary greatly over time. Beyond the peak and off-peak<br />

performance differences, one must also consider the variations over a given period, for<br />

example, the morning rush hour. For the operator, the variability of travel time for a given<br />

period makes it more difficult to draw up the timetables. For the passengers, the<br />

uncertainty of travel times means that they have to allow greater safety margins for all trips<br />

that require that they reach their destination at a specific time.<br />

The irregularity of travel time is easy to detect through their standard deviations for a given<br />

period. This methodological approach shows that the geography of irregularity during the<br />

morning peak hours is not identical to that of commercial speed.<br />

Analysis of time lost by the vehicles in a day<br />

As soon as the commercial speed fluctuates, one can assume that the deterioration in the<br />

travel time compared with the periods of maximum fluidity (early in the morning or late at<br />

night) entails a time loss for the vehicles. This time loss can be calculated from the<br />

difference between the travel time at each period of the day and a fluid reference period (in<br />

that case, from 9 to 10 p.m.), multiplied by the number of passes on the line.<br />

In this analysis it is obtained the amounts of time lost on the bus and tram networks at the<br />

end of a day calculated from the differences in travel times compared with the fluid<br />

situation observed between 9 and 10 p.m.<br />

Measuring transport reliability consists to define indicators that provide appropriate<br />

measures of the inconsistency in travelling within the network. It is possible distinguish<br />

between the network provider or operator and the user point of views. For the network<br />

| Short term Scientific Mission -ITALY 15


provider the reliability indicators must focuses on the system robustness (or vulnerability)<br />

and on its operating performance. The used indicators are for example, the connectivity of<br />

the network, its capacity to respond to unpredictable demand or the supply conditions<br />

offered by a degraded network, etc.<br />

From the user point of view, the invariability of the experienced travel time corresponds to<br />

the main index. Indicators must focus on this travel time variability quantification. Several<br />

definitions for travel time reliability exist and many different relevant indicators have been<br />

proposed (Lomax et al. (2003); Van Lint (2004)). Some of them are statistical range<br />

indicators such as the “Standard Deviation” or the “Variation Coefficient” computed for a<br />

given time of day or day of a week. Other approaches are related to the Buffer Index, the<br />

tardy trips and width of the travel time distribution. Depending on the travel time<br />

reliability study, it may be more appropriate to use one indicator than another. For<br />

example, the standard deviation (or spread) of travel times can be advised as cost effective<br />

measures to monitor travel time variation and reliability, however the buffer index<br />

indicator can be more useful for the users information.<br />

In the literature, the Buffer Index appears to relate particularly well to the way in which<br />

travelers make their decisions (TRB/NCHRP, 2008). The investigations are focused on<br />

these indicators to compare the impact of the ramp metering on the travel time reliability.<br />

Buffer Index (BI): is defined as the extra time a user has to add to the average travel time<br />

so one is on time 95% of the time. It is computed as the difference between the 95th<br />

percentile travel time (TT 95 ) and mean travel time (M), divided by mean travel time.<br />

1<br />

2BI = (TT 95 –M)/M<br />

3<br />

The 95th Percentile Travel Time (TT 95 ) expresses how much delay will be on the heaviest<br />

travel days. The Buffer Index is useful in the user’s assessment of how much extra time<br />

has to be allowed for uncertainty in the travel conditions. It hence answers simple<br />

questions such as “How much time do I need to allow?” “When should I leave?” For<br />

example, if the average travel time, M = 20 minutes, the Buffer index, BI=40 %, the Buffer<br />

time = 20 × 0.40 = 8 minutes. Therefore, the traveler should allow 28 minutes for their trip<br />

in order to ensure on-time arrival 95 percent of the journey time.<br />

4<br />

| Short term Scientific Mission -ITALY 16


Planning Time Index: total time needed to plan for an on-time arrival 95% of the time as<br />

compared to the free flow travel time. It is computed as 95th percentile travel time (TT 95 )<br />

divided by free-flow travel time (TT free-flow ):<br />

5<br />

6PTI = TT 95 / TT free-flow<br />

7<br />

For example, a PTI= 1.60, TT free-flow = 15 minutes, a traveler should plan 24 minutes in total<br />

to ensure on-time arrival at 95% of the time.<br />

Because these indicators one can use the 95-percentile value of the travel time distribution<br />

as a reference of the definitions, they take into account more explicitly the extreme travel<br />

time delays.<br />

Travel Time Index: average time it takes to travel during peak hours compared to free flow<br />

conditions, computed as mean travel time divided by free flow travel time.<br />

8<br />

9TTI = M/ TT free-flow<br />

10<br />

TTI indicator is known as a congestion indicator and will be used to compare the reliability<br />

with the congestion states (see Fig.1.3).<br />

Fig. 1.3- Reliability indicators relationship (Turner, 2006)<br />

| Short term Scientific Mission -ITALY 17


CHAPTER II – PROPOSED APRROACH TO EVALUATE <strong>RELIABILITY</strong> ON<br />

PUBLIC TRANSPORT SERVICES<br />

In this chapter will follow a scientific methodology useful for application in different<br />

contexts in order to analyze and compare different performances of Public Transport.<br />

There is a different approach in function of the service type (represented by runs or<br />

frequency), because the user behavior is different and changes with the different<br />

company’s supply. The following approach was used during the <strong>BHLS</strong> studying phase<br />

within the missions abroad.<br />

2.1 Definition of reliability<br />

A useful definition recognizes that users plan their actions in function of the network<br />

performances. That’s why they defined reliability as “The ability of the transport system to<br />

provide the expected level of service quality, on which users have organized their<br />

activities” (OCDE, September 2009). According to this definition, reliability can be<br />

improved either by supplying better reliability or by changing expectations of the level of<br />

reliability. The expectations of public transport reliability are linked with the service type<br />

(runs or frequency) and from these differences will follow different user behavior,<br />

according to the random utility theory in which the user makes a “rational decision.”<br />

Reliability indicators, that are tightly linked to the objectives of different parties (service<br />

provider, users and community), need to be evaluated differently in the two types of public<br />

transport service.<br />

Particularly reliability can be subdivided as:<br />

punctuality- the adherence between the scheduled time and the real time (at the<br />

departure, during the trip and at the destination arrival);<br />

regularity- the respect of the frequency during a window time;<br />

crisis- the capability to fix unexpected problems that can break the regularity of<br />

service.<br />

| Short term Scientific Mission -ITALY 18


2.2 Definition of the service typologies<br />

The supply system for public transport can be modeled through the graph theory.<br />

Particularly there are two different methods to represent, and it depends if the link i-j is just<br />

a spatial connection or also has a temporal connotation given by the time in which the<br />

service is active.<br />

Subsequently the word “line” will be used to indicate the path followed by a mean of<br />

transportation made by a sequence of stops; on the other hand the word “run” will be used<br />

to refer to a space-time path, made by a sequence of stops with a set time of departure and<br />

arrival at the bus stop.<br />

It follows that the generic link that represent the service, in the first case, will have<br />

associated the line features, on the other hand the second will have the features of the<br />

single run; it will be possible to obtain the system representation through a line based<br />

graph for frequency network and a run based graph for the time approach.<br />

2.3. Approaches for estimating the value of reliability<br />

2.3.1 Run based services<br />

The reliability, as said, is mainly function of delay time that present the transport system in<br />

the different singular points (stops) toward to a scheduled time.<br />

The steps to be followed are generally carried out in this order:<br />

characterization of the system from the infrastructural point of view;<br />

definition and modeling of the transport lines;<br />

modeling of the runs within each transport lines;<br />

analysis of the transport company database;<br />

confrontation between real times (relieved on board) and scheduled times;<br />

construction of the diachronic graph with the real time and scheduled time;<br />

calculation of the reliability indicators.<br />

The first analysis of reliability characterizes the transport system by the infrastructural<br />

features of the lines and subsequently focalizes the attention on the runs of each lines.<br />

| Short term Scientific Mission -ITALY 19


This phase is characterized by the collection of geometric data of the transport lines and<br />

the analysis of the technological characteristics of the transport vectors and information<br />

(ITS, Intelligent Transport System).<br />

Subsequently the analysis is based on the relief on board of transport system data and then<br />

subsequently on the confrontation between real times (relieved on board) and scheduled<br />

times; in this way it is underlined the value of delay time that the transport system<br />

produces on the terminals and on the stops with negative consequences for the users.<br />

The differences between real times and scheduled times can be underlined trough an<br />

instrument that is the diachronic graph. The diachronic graph consists of representing<br />

every run of every line, with the representation of the time variable related to the schedule<br />

of the service. The graph produced with this change is said diachronic graph: one general<br />

exemplification inherent the representation of the runs is brought in the Fig.2.1.<br />

.<br />

Fig.2.1- Example of diachronic graph.<br />

Within the diachronic graph it is possible to represent the differences between the real<br />

times and scheduled times underlining the possible critical points of the system (Fig. 2.2).<br />

This procedure must affect every run of the transport lines.<br />

.<br />

| Short term Scientific Mission -ITALY 20


Fig.2.2- Example of diachronic graph that underlines differences of the times<br />

The calculation of reliability indicators is based on the relief of the delay times and then on<br />

the irregularity of the transport system.<br />

The main reliefs that can be effected are the following:<br />

differences between the real times and scheduled times on the stops and on the<br />

terminals;<br />

delay time accumulated;<br />

number of the runs deleted;<br />

number of the runs that respect the scheduled time for the stops and the terminal.<br />

With these measures it is possible to obtain a series of reliability indicators, that can be<br />

calculated as follows:<br />

Variability on the stops(Arrival Time, Departure Time, Travel Time): V= ∑∆ i / N° f<br />

;<br />

Crisis of System : % failed runs: F= R F /R T ;<br />

Delay accumulated on stops: D= ∑ D i ;<br />

% runs on time : OR= R O /R T .<br />

2.3.2. Frequency based services<br />

| Short term Scientific Mission -ITALY 21


The frequency-based modeling approach refers to a line-based supply representation, for<br />

which assignment results can be carried out in terms of average flow on each line.<br />

The system line representation, allow to:<br />

a) not explicit the service time;<br />

b) share the access/egress system with other systems;<br />

c) reduce to the most important components the services network.<br />

On the Fig. 2.3 is showed a scheme of a particular high frequency network, whose stop<br />

node is divided by 2 different nodes, one represents the access/egress node that is the<br />

stop’s spatial location, the other (called diversion node) represent the happened decision of<br />

the user to use the public transport service in that stop; all these nodes are connected by<br />

links, as showed on Fig. 2.3.<br />

Fig. 2.3 - Modeling of stop for high frequency services<br />

The steps to be followed can be, in general, resumed in:<br />

characterization of the system from the infrastructural point of view;<br />

definition and modeling of the transport lines;<br />

modeling of the service line within the System Transport;<br />

| Short term Scientific Mission -ITALY 22


analysis of the transport company database;<br />

confrontation between real times (relieved on board) and scheduled times;<br />

calculation of the reliability indicators.<br />

The calculation of reliability indicators is based on the relief of the passages times on the<br />

stops and then on the irregularity of the transport system in this stops.<br />

The main reliefs that can be effected are the followings:<br />

differences between the real frequency and scheduled frequency on the stops;<br />

differences between the frequency during the different time periods;<br />

number of the runs that failed the scheduled frequency;<br />

the dwell time on the stops of the line;<br />

The main reliability indicators that it is possible to obtain are the follows:<br />

Frequency irregularity (FR), expressed as Standard Deviation of average frequency:<br />

FR=[∑ i=1,..,n (x i –AF) 2 /n] 1/2<br />

where:<br />

n = number of passages;<br />

x i = punctual frequency;<br />

AF = Average frequency.<br />

<strong>RELIABILITY</strong>, % of runs that respect the scheduled frequency:<br />

<strong>RELIABILITY</strong> = 1 - R F /R Tot ;<br />

where:<br />

R F = number of failed runs respect to the scheduled frequency;<br />

R Tot = total number of runs.<br />

CHAPTER III – ORGANIZATION AND EXECUTIONS <strong>OF</strong> THE <strong>RELIABILITY</strong><br />

ANALYSIS ON SITE<br />

3.1. Operations on site : characteristics of the analyzed line<br />

| Short term Scientific Mission -ITALY 23


During the Short Mission in Manchester the studies have been addressed to the <strong>BHLS</strong> on<br />

the route 192 (Manchester City Centre - Hazel Grove, Fig.3.1), because this route during<br />

the peak hours is very congested. The 192 route currently runs along the A6 corridor<br />

between Hazel Grove and Manchester City Centre. It commences at A523 Macclesfield<br />

Road (Bus Layby), travels along the A6 London Road, A6 Buxton Road, A6 Wellington<br />

Road, A6 Stockport Road onto Ardwick Green South and into the city centre. The 192<br />

route is approximately 14.9 km long inbound and 14.7 km long on the outbound journey. It<br />

takes an average of nearly 68 minutes to travel between Hazel Grove and Manchester City<br />

in the morning and just over 58 minutes in the evening peak.<br />

Fig.3.1. Route 192 (Manchester – Hazel Grove)<br />

Fig.3.2. Details of Route 192 (Manchester – Hazel Grove)<br />

| Short term Scientific Mission -ITALY 24


There are a high number of notable junction delays travelling inbound during the<br />

morning peak. The most significant delays occur at:<br />

A6 London Road / Hope Street;<br />

London Road / Commercial Road;<br />

Junctions between A6 Buxton Road / Woodsmoor Lane and Wellington Road<br />

South /Longshut Lane;<br />

A6 Stockport Road / Hulme Street ;<br />

A6 Stockport Road / Albert Road;<br />

A6 Stockport Road / Slade Lane traffic signals;<br />

A6 London Road / Fairfield Street traffic signals.<br />

Travelling outbound towards Hazel Grove in the evening peak notable junction delay<br />

problems occur at:<br />

A6 Stockport Road / Plymouth Grove;<br />

Kirkmanshulme Lane and Cromwell Grove traffic signals;<br />

Wellington Road North / School Lane;<br />

Wellington Road South / St Petersgate;<br />

Wellington Road South / Higher Hillgate;<br />

A6 London Road / Fairfield Street and;<br />

A6 London Road / Store Street.<br />

There are a total of 30 critical junctions along this corridor that are a cause of delay to<br />

buses and should therefore be prioritized for review. In addition, eleven high priority<br />

junctions have been identified.<br />

There are 52 bus stops northbound and 49 southbound between Manchester and Hazel<br />

Grove.<br />

Northbound in the morning peak, bus stops SG3998 Kennerley Road and SG4000<br />

Nangreave Road show higher than expected delays and should be prioritized for review.<br />

No southbound stops have been identified as requiring review.<br />

The following figure sets out the results of this route performance review, illustrating<br />

critical junctions; bus stops and links where current performance is significantly below<br />

standards and; where intervention is likely to deliver the greatest benefits to buses.<br />

| Short term Scientific Mission -ITALY 25


Fig.3.3. Junction delays of route 192<br />

| Short term Scientific Mission -ITALY 26


Tab.3.1. Main characteristics of route 192<br />

Bus Route<br />

District/s<br />

Section Assessed<br />

Section Length<br />

Source Data<br />

Analysis Data<br />

Route 192 Hazel Grove - Manchester<br />

Stockport / Manchester<br />

Hazel Grove – Manchester<br />

14.9km Inbound, 14.7km Outbound<br />

…Data\Route 192 Manchester to Hazel Grove \QBC Bus Service 192 to Manchester<br />

Nov 2008.xls<br />

…\Reports\Analysis\Route 192.xls<br />

Date of Source Data November 2008<br />

GMTU Report<br />

…\Data\Route 192 Manchester-Hazel Grove \GMTU Rep1356 Manchester Hazel<br />

Grove QBC November 2008 .doc<br />

Tab.3.2. Performance summary of route 192<br />

Performance Summary<br />

Hazel Grove - Manchester<br />

AM<br />

Inbound<br />

PM<br />

Outbound<br />

Bus average total journey time including dwell time (hh:mm:ss) 01:07:44 00:58:28<br />

Bus average total journey time excluding dwell time (hh:mm:ss) 00:51:15 00:47:53<br />

Bus average journey time per km (hh:mm:ss) 00:04:33 00:03:59<br />

Bus average speed inc. boarding and alighting (kmh) 13.19 15.05<br />

Frequency of traffic signal Junctions (m) 355 366<br />

Frequency of pedestrian crossings (m) 514 490<br />

Frequency of Bus Stops (m) 287 300<br />

Total junction and pedestrian crossing delays (hh:mm:ss) 00:18:57 00:17:44<br />

% of all junction/pedestrian crossing on route 28% 30%<br />

Total bus stop dwell time on route (hh:mm:ss) 00:16:29 00:10:35<br />

% dwell time on route (hh:mm:ss) 24% 18%<br />

Variability (CoV) 9.29 10.32<br />

In summary:<br />

o<br />

the 192 service currently takes an average of nearly 68 minutes to travel between<br />

Hazel Grove and Manchester City in the morning and just over 58 minutes in the<br />

evening peak;<br />

o<br />

the frequency of traffic signal junctions is average for this type of corridor; but the<br />

frequency of pedestrian crossings and bus stops is low and;<br />

o<br />

the percentage of journey time attributable to dwell time is 6% higher in the morning<br />

peak.<br />

3.2. Collected Data<br />

| Short term Scientific Mission -ITALY 27


During the mission and the interviews with GMPTE managers, a discussion about the<br />

performances of the service, about investments and about future programs has been<br />

developed; particularly the GMPTE has furnished a series of data on the rout 192 listed<br />

following:<br />

Performance summary (See Table 3.2, AM inbound & PM outbound)<br />

Junction Delays Map (Critical points)<br />

Bus average total journey time including dwell time<br />

Bus average total journey time excluding dwell time<br />

Bus average journey time per km<br />

Bus average speed incl. boarding and alighting<br />

Frequency of traffic signal junctions<br />

Frequency of pedestrian crossings<br />

Frequency of bus stops<br />

Total junction and pedestrian crossing delays<br />

% of all junction/pedestrian crossing on route<br />

Total bus stop dwell time on route<br />

% dwell time on route<br />

Variability (CoV)<br />

Comparison with Network Averages<br />

JUNCTION DELAYS Inbound & Outbound<br />

| Short term Scientific Mission -ITALY 28


Intersection, Type of intersection, Average delay time (sec), Difference from<br />

average<br />

Timing<br />

Point<br />

Tab.3.3. Example of data of junction delay<br />

Route Intersection type Intersection with<br />

Junction<br />

aver.delay (s)<br />

A523 Macclesfield Road (Bus<br />

1 Layby) Traffic Signals A523 Macclesfield Road<br />

40,30<br />

2 A523 Macclesfield Road Traffic Signals A6 London Road 3,03<br />

3 A6 London Road Bus Stop SG4010 Norbury Church (Stop B) 7,23<br />

4 A6 London Road Traffic Signals A627 Torkington Road 12,70<br />

5 A6 London Road Traffic Signals Brook Street (McDonalds) 3,07<br />

6 A6 London Road Bus Stop SG4011 Torkington Road 14,27<br />

7 A6 London Road Signalised Pedestrian Grundy Street (Queens Road) 8,27<br />

8 A6 London Road Bus Stop SG4018 Queens Road 25,30<br />

9 A6 London Road Signalised Pedestrian Hatherlow Lane (Chapel St) 2,93<br />

10 A6 London Road Signalised Pedestrian Hope Street (Vine St) 36,77<br />

11 A6 London Road Traffic Signals Commercial Road 47,83<br />

12 A6 London Road Bus Stop SG4001 Commercial Road 45,87<br />

13 A6 London Road Signalised Pedestrian Brewers Green (Vernon St) 15,23<br />

…... ……………… ……………… ……………… …...<br />

BUS STOP DELAYS Inbound & Outbound<br />

Average times per passenger in seconds<br />

BUS STOP ANALYSES Inbound & Outbound<br />

Average delay<br />

Average passengers (boarders and alighted)<br />

Expected boarding and alighting delay<br />

Total expected delay<br />

EWT ANALYSES<br />

Stop description, Service, Actual time, Destination, Level of traffic, Weather, Time<br />

period, Actual difference, Expected waiting time for stops (EWT).<br />

Besides a review has been effected on board of the journey time and dwell time of a<br />

generic run in the considered peak hours (9 March 2009, see Tables 3.4).<br />

During the review dwell times on the stops of the single analyzed runs were collected. A<br />

comparison was operated with the average values elaborated by the GMPTE.<br />

Tab. 3.4a. Data collected on-board (Run 9,30 : Manchester-Hazel Grove)<br />

| Short term Scientific Mission -ITALY 29


Stop<br />

Arrival time<br />

(hh,mm)<br />

Departure time<br />

(hh. mm)<br />

Dwell time<br />

(sec)<br />

Piccadilly 9,29 9,30 60<br />

Apollo teathre 9,34 9,34 30<br />

Longhsit Shopping Centre 9,38 9,38 20<br />

Slade lane 9,41 9,41 40<br />

Matthews Lane 9,43 9,43 10<br />

Carrill Grove 9,44 9,44 10<br />

Broom lane 9,46 9,46 7<br />

Heaton Road 9,52 9,52 40<br />

Belmont way 9,54 9,55 60<br />

Mersey square 9,56 9,59 180<br />

Grand Central 10,00 10,00 20<br />

Stockport college 10,01 10,02 40<br />

Brentnall street 10,03 10,03 7<br />

Longshut lane 10,03 10,04 20<br />

Nangreave Road 10,05 10,06 15<br />

Kennerley Road 10,06 10,07 15<br />

Corbar road 10,07 10,07 10<br />

Cherry Tree Lane 10,09 10,09 20<br />

Dialstone Lane 10,09 10,09 7<br />

Stepping Hill Hospital 10,11<br />

Tab. 3.4b. Data collected on-board (Run 10,20 : Hazel Grove-Manchester)<br />

Arrival time Departure time Dwell time<br />

Stop<br />

(hh,mm) (hh. mm) (sec)<br />

Dialstone Lane 10,20<br />

Corbar Road 10,22 10,22 15<br />

Nangreave Road 10,24 10,24 10<br />

Wellington Grove 10,26 10,26 10<br />

Stockport College 10,27 10,28 20<br />

Grand Central 10,30 10,31 60<br />

Mersey Square 10,32 10,35 150<br />

Belmont Bridge 10,37 10,37 15<br />

Heaton Road 10,38 10,38 20<br />

Milwain Drive 10,41 10,41 10<br />

Lloyd Road 10,43 10,44 40<br />

Broom Lane 10,45 10,45 15<br />

Albert Road 10,48 10,48 15<br />

Woodford Avenue 10,50 10,50 10<br />

East Road 10,52 10,53 30<br />

Longsight H. Centre 10,55 10,57 80<br />

Plymouth Grove 10,59 11,00 30<br />

Winterford A. 11,01 11,01 15<br />

Devonshire Street 11,02 11,02 10<br />

| Short term Scientific Mission -ITALY 30


Covanagh Close 11,02 11,03 10<br />

Apollo theatre 11,02 11,03 7<br />

Travis Street 11,05 11,05 10<br />

Minshull Street 11,07 11,07 7<br />

Piccadilly 11,00<br />

Tab. 3.4c. Data collected on-board (Run 17,48 : Manchester-Hazel Grove)<br />

Arrival time Departure time Dwell time<br />

Stop<br />

(hh,mm) (hh. mm) (sec)<br />

Piccadilly (Paton street) 17,48 17,48 20<br />

Fairfield Street 17,50 17,50 20<br />

Travis Street 17,51 17,52 20<br />

Ardwick Green 17,52 17,53 10<br />

Apollo Theatre 17,54 17,54 10<br />

Ardwick Post Office 17,54 17,55 10<br />

Devonshire Street 17,55 17,56 10<br />

Plymouth Grove W. 17,56 17,57 7<br />

Plymouth Grove 17,57 17,57 10<br />

Longsight S.Centre 17,59 17,59 15<br />

Slade Lane 18,01 18,02 20<br />

Matthews Lane 18,03 18,03 7<br />

Mayfield Road 18,04 18,05 10<br />

Carrill Grove 18,05 18,05 7<br />

Albert Road 18,07 18,07 7<br />

Delamere Road 18,08 18,08 7<br />

McVities 18,11 18,11 7<br />

Manchester Road 18,12 18,12 7<br />

Heaton Moor Road 18,14 18,14 10<br />

Terminal<br />

Tab. 3.4d. Data collected on-board (Run 18,27 : Hazel Grove-Manchester)<br />

Arrival time Departure time Dwell time<br />

Stop<br />

(hh,mm) (hh. mm) (sec)<br />

Mersey square 18,27<br />

Belmont way 18,29 18,29 10<br />

Belmont bridge 18,29 18,29 10<br />

Brackley road 18,32 18,32 7<br />

Heaton Moor road 18,33 18,33 15<br />

Manchester Road 18,34 18,34 10<br />

Milwain drive 18,35 18,35 25<br />

Lloyd road 18,37 18,37 25<br />

Broom lane 18,38 18,38 15<br />

Crayfield road 18,39 18,39 25<br />

| Short term Scientific Mission -ITALY 31


Albert road 18,40 18,41 15<br />

Carrill Grove 18,42 18,43 35<br />

Woodford Avenue 18,44 18,44 10<br />

Matthews lane 18,45 18,45 7<br />

East road 18,46 18,46 15<br />

Slade lane 18,47 18,47 20<br />

Longhsit health centre 18,49 18,49 30<br />

Plymouth grove 18,51 18,51 7<br />

Plymouth grove west 18,52 18,52 15<br />

Winterford avenue 18,53 18,53 10<br />

Devonshire Street 18,53 18,54 10<br />

Covanagh Close 18,54 18,54 15<br />

Apollo theatre 18,55 18,56 40<br />

Grosvenor Street 18,57 18,57 10<br />

Travis Street 18,58 18,58 15<br />

Minshull Street 19,00 19,00 7<br />

Piccadilly 19,03<br />

Fig.3.4 – Comparison between average delay at bus stop and data collected<br />

(Run 10,20 : Hazel Grove-Manchester)<br />

| Short term Scientific Mission -ITALY 32


Fig.3.5 – Comparison between average delay at bus stop and data collected<br />

(Run 17,48 : Manchester – Hazel grove)<br />

From the diagram in Fig. 3.4 and Fig. 3.5 it is possible to observe as in the run analyzed in<br />

direction Manchester (AM Peak) that the values collected of the dwell times are very large<br />

versus the average in some stops, especially in the mains. While in the run of the afternoon<br />

the values are still below the average.<br />

An analysis is developed also considering the database furnished by the GMPTE (gives<br />

related to the period 29/09/2008-10/10/2008 and to the AM Peak period time in direction<br />

Manchester starts at 7,30 until the 9,30 and PM Peak in direction Hazel Grove that it has<br />

gone since 16,30 to 18,30 o'clock) on the delays that the line 192 accumulate during the<br />

travel; these are due to the numerous intersections along the line. In the table 3.5 are listed<br />

the intersections and the stops along the line and the relative average delays.<br />

| Short term Scientific Mission -ITALY 33


Table. 3.5. Average junction delay on route 192 – Towards Manchester AM Peak<br />

Timing<br />

Point<br />

Route Intersection type Intersection with<br />

Junction<br />

Av Delay<br />

(s)<br />

A523 Macclesfield Road (Bus<br />

1 Layby) Traffic Signals A523 Macclesfield Road<br />

40,30<br />

2 A523 Macclesfield Road Traffic Signals A6 London Road 3,03<br />

3 A6 London Road Bus Stop SG4010 Norbury Church (Stop B) 7,23<br />

4 A6 London Road Traffic Signals A627 Torkington Road 12,70<br />

5 A6 London Road Traffic Signals Brook Street (McDonalds) 3,07<br />

6 A6 London Road Bus Stop SG4011 Torkington Road 14,27<br />

7 A6 London Road Signalised Pedestrian Grundy Street (Queens Road) 8,27<br />

8 A6 London Road Bus Stop SG4018 Queens Road 25,30<br />

9 A6 London Road Signalised Pedestrian Hatherlow Lane (Chapel St) 2,93<br />

10 A6 London Road Signalised Pedestrian Hope Street (Vine St) 36,77<br />

11 A6 London Road Traffic Signals Commercial Road 47,83<br />

12 A6 London Road Bus Stop SG4001 Commercial Road 45,87<br />

13 A6 London Road Signalised Pedestrian Brewers Green (Vernon St) 15,23<br />

14 A6 London Road Bus Stop SG0908 Brewers Green 9,80<br />

15 A6 London Road Traffic Signals Mill Street 24,17<br />

16 A6 London Road Traffic Signals New Moor Lane (Sainsbury's) 0,00<br />

17 A6 Buxton Road Bus Stop SG4004 Sainsbury's 16,57<br />

18 A6 Buxton Road Traffic Signals Poplar Grove (Dialstone Ln) 24,27<br />

19 A6 Buxton Road Signalised Pedestrian Dialstone Lane (Bonis Crs) 1,80<br />

20 A6 Buxton Road Bus Stop SG4002 Dialstone Lane (Stop A) (OTP) 23,57<br />

21 A6 Buxton Road Signalised Pedestrian Norwood Road (Cherry Tree Lane) 14,70<br />

22 A6 Buxton Road Bus Stop SG4003 Cherry Tree Lane 19,97<br />

23 A6 Buxton Road Signalised Pedestrian Woodsmoor Lane (Lake St) 31,60<br />

24 A6 Buxton Road Bus Stop SG4005 Woodsmoor Lane 16,73<br />

25 A6 Buxton Road Signalised Pedestrian Mile End Lane 29,73<br />

26 A6 Buxton Road Bus Stop SG3996 Corbar Road 5,70<br />

27 A6 Buxton Road Traffic Signals Kennerley Road 61,37<br />

28 A6 Buxton Road Bus Stop SG3998 Kennerley Road 30,60<br />

29 A6 Buxton Road Signalised Pedestrian Heaviley Grove (Regent Rd) 10,87<br />

30 A6 Buxton Road Bus Stop SG3999 Heaviley Post Office (OTP) 8,13<br />

31 A6 Buxton Road Traffic Signals B6171 Nangreave Road 35,60<br />

32 A6 Buxton Road Bus Stop SG4000 Nangreave Road 66,23<br />

33 A6 Buxton Road Bus Stop SG0864 Bramhall Lane 4,03<br />

34 A6 Buxton Road Traffic Signals A5102 Bramhall Lane 45,60<br />

35 A6 Wellington Road South Bus Stop SG3985 Wellington Grove (A) 15,90<br />

36 A6 Wellington Road South Signalised Pedestrian Wellington Grove (Daisy St) 5,83<br />

37 A6 Wellington Road South Traffic Signals B5465 Longshut Lane 43,67<br />

38 A6 Wellington Road South Bus Stop SG3986 Longshut Lane 20,67<br />

39 A6 Wellington Road South Signalised Pedestrian Charlesworth Street (Brentnall St) 5,43<br />

40 A6 Wellington Road South Signalised Pedestrian Stockport College 0,00<br />

41 A6 Wellington Road South Bus Stop SG3987 Stockport College (Stop AC) 22,73<br />

42 A6 Wellington Road South Signalised Pedestrian Ratcliffe Street 2,97<br />

Stockport Town Hall (Greek Street) (1st<br />

43 A6 Wellington Road South Traffic Signals Set)<br />

12,07<br />

Traffic Signals With<br />

44 A6 Wellington Road South Pedestrian Facilities Stockport Town Hall (2nd Set)<br />

0,13<br />

45 A6 Wellington Road South Traffic Signals Railway Road (John St) 2,03<br />

46 A6 Wellington Road South Bus Stop SG1627 Grand Central (Stop WW) 38,63<br />

47 A6 Wellington Road South Traffic Signals Grand Central Complex (Station Road) 26,70<br />

48 A6 Wellington Road South Traffic Signals Exchange Street (St Petersgate) 3,17<br />

49 A6 Wellington Road South Traffic Signals Heaton Lane 3,23<br />

50 A6 Wellington Road North Bus Stop SG0926 Mersey Square (Stop AA) (OTP) 84,30<br />

51 A6 Wellington Road North Signalised Pedestrian Wellesley House 0,50<br />

52 A6 Wellington Road North Bus Stop SG1664 Aspley House 1,77<br />

53 A6 Wellington Road North Traffic Signals George's Road 9,27<br />

54 A6 Wellington Road North Bus Stop SG3991 Belmont Way 4,27<br />

55 A6 Wellington Road North Traffic Signals Belmont Way 9,03<br />

56 A6 Wellington Road North Bus Stop SG3992 Belmont Bridge 8,17<br />

57 A6 Wellington Road North Traffic Signals Heaton Road 12,37<br />

58 A6 Wellington Road North Bus Stop SG3993 Heaton Road 11,53<br />

59 A6 Wellington Road North Signalised Pedestrian Warwick Road (Glenfield Rd) 0,30<br />

60 A6 Wellington Road North Bus Stop SG1052 Warwick Road (OTP) 8,00<br />

61 A6 Wellington Road North Signalised Pedestrian Langford Road (Brackley Rd) 0,63<br />

| Short term Scientific Mission -ITALY 34


62 A6 Wellington Road North Bus Stop SG1267 Brackley Road 8,57<br />

63 A6 Wellington Road North Traffic Signals B5169 Heaton Moor Road (School Lane) 18,70<br />

64 A6 Wellington Road North Bus Stop SG0596 Heaton Moor Road (Stop A) 17,50<br />

65 A6 Wellington Road North Traffic Signals A626 Manchester Road 13,10<br />

66 A6 Wellington Road North Bus Stop SG0593 Manchester Road 14,60<br />

67 A6 Wellington Road North Signalised Pedestrian Milwain Drive 1,07<br />

68 A6 Wellington Road North Bus Stop SG0594 Milwain Drive 4,70<br />

69 A6 Wellington Rd North Signalised Pedestrian Weybrook Road 0,63<br />

70 A6 Wellington Rd North Bus Stop SG0595 McVities 16,80<br />

71 A6 Wellington Road North Traffic Signals Crossley Road 26,80<br />

72 A6 Wellington Road North Traffic Signals Lloyd Road 0,00<br />

73 A6 Stockport Road Bus Stop EB0366 Lloyd Road (OTP) 14,70<br />

74 A6 Stockport Road Signalised Pedestrian Cringle Road 13,57<br />

75 A6 Stockport Road Traffic Signals B6178 Broom Lane 14,10<br />

76 A6 Stockport Road Signalised Pedestrian Hume St (Darnforth Gr) 25,80<br />

77 A6 Stockport Road Bus Stop EB0365 Broom Lane 19,10<br />

78 A6 Stockport Road Signalised Pedestrian Crayfield Road 48,27<br />

79 A6 Stockport Road Bus Stop EB0362 Crayfield Road 16,27<br />

80 A6 Stockport Road Traffic Signals Alma Road 86,40<br />

81 A6 Stockport Road Bus Stop EB0361 Albert Road 13,27<br />

82 A6 Stockport Road Traffic Signals B5093 Albert Road 57,87<br />

83 A6 Stockport Road Signalised Pedestrian Cromwell Grove 3,10<br />

84 A6 Stockport Road Bus Stop EB0359 Carrill Grove 66,67<br />

85 A6 Stockport Road Signalised Pedestrian Woodford Avenue (Mayford Ave) 5,40<br />

86 A6 Stockport Road Bus Stop EB0357 Woodford Avenue 13,57<br />

87 A6 Stockport Road Traffic Signals Matthews Lane 4,57<br />

88 A6 Stockport Road Bus Stop EB0355 Matthews Lane 18,57<br />

89 A6 Stockport Road Traffic Signals Crowcroft Road 1,60<br />

90 A6 Stockport Road Bus Stop EB0449 East Road 18,83<br />

91 A6 Stockport Road Bus Stop EB0446 Slade Lane (OTP) 33,20<br />

92 A6 Stockport Road Traffic Signals A5079 Slade Lane 66,60<br />

93 A6 Stockport Road Traffic Signals A6010 Dickenson Road 12,37<br />

94 A6 Stockport Road Bus Stop EB0614 Longsight Health Centre (Stop A) 57,30<br />

95 A6 Stockport Road Signalised Pedestrian Longsight District Centre 7,10<br />

96 A6 Stockport Road Traffic Signals A6010 Kirkmanshulme Lane 24,07<br />

97 A6 Stockport Road Traffic Signals A5184 Plymouth Grove 5,57<br />

98 A6 Stockport Road Bus Stop EB0617 Plymouth Grove 22,33<br />

99 A6 Stockport Road Bus Stop EB0618 Longsight Police Station 9,93<br />

100 A6 Stockport Road Signalised Pedestrian Plymouth Grove West 2,63<br />

101 A6 Stockport Road Bus Stop EB0619 Plymouth Grove West 8,40<br />

102 A6 Stockport Road Bus Stop EB0620 Winterford Avenue 8,87<br />

103 A6 Stockport Road Signalised Pedestrian Winterford Avenue 2,47<br />

104 A6 Stockport Road Signalised Pedestrian Grove Village 0,80<br />

105 A6 Stockport Road Bus Stop EB0621 Devonshire Street 14,97<br />

106 A6 Stockport Road Traffic Signals A665 Devonshire Street 14,60<br />

107 A6 Stockport Road Bus Stop EB0624 Cavanagh Close 20,57<br />

108 A6 Stockport Road Bus Stop EB0623 Apollo Theatre (OTP) 13,17<br />

109 A6 Stockport Road Signalised Pedestrian Apollo Theatre 1,93<br />

110 A6 Stockport Road Roundabout Entry A6 Ardwick Green South 15,00<br />

111 A6 Ardwick Green South Signalised Pedestrian Apollo Roundabout 0,30<br />

112 A6 Ardwick Green South Bus Stop EB3420 Ardwick Green 6,73<br />

113 A6 Downing Street Bus Stop EB3417 Grosvenor Street 6,03<br />

114 A6 Downing Street Traffic Signals Grosvenor Street 7,60<br />

115 A6 Downing Street Traffic Signals A57(m) Mancunian Way 8,87<br />

116 A6 London Road Bus Stop EB0116 Travis Street 12,83<br />

117 A6 London Road Traffic Signals B6469 Farfield Street 26,37<br />

118 A6 London Road Traffic Signals A6 Whitworth Street 3,30<br />

119 A6 Whitworth Street Bus Stop EB0255 Fairfield Street 12,93<br />

120 A6 Whitworth Street Traffic Signals A6 Aytoun Street 2,43<br />

121 A6 Aytoun Street Bus Stop A523 Macclesfield Road 8,93<br />

122 A6 Aytoun Street Traffic Signals A6 London Road 0,37<br />

123 A6 Aytoun Street Traffic Signals SG4010 Norbury Church (Stop B) 41,20<br />

124 A5103 Portland Street Bus Stop A627 Torkington Road 0,00<br />

From these data, it results that in direction Manchester the service during the journey<br />

accumulates in average 1151,7 seconds (19,2 minutes) on the intersections and 989,3<br />

seconds (16,48 minutes) on the stops.<br />

| Short term Scientific Mission -ITALY 35


In table 3.6 the average delays accumulated by the service in direction Hazel Grove are<br />

presented.<br />

Timing<br />

Point<br />

Table. 3.6. Average junction delay on route 192 – Towards Hazel Grove PM Peak<br />

Route Intersection type Intersection with<br />

Av<br />

Junction<br />

Delay (s)<br />

1 A6 Piccadilly Signalised Pedestrian Paton Street 11,80<br />

2 A6 Piccadilly Traffic Signals Ducie Street 23,20<br />

3 A6 London Road Traffic Signals Store Street (Metrolink Crossing) 29,70<br />

4 A6 London Road Bus Stop EB0120 Fairfield Street (Stop A) 25,17<br />

5 A6 London Road Traffic Signals B6469 Fairfield Street 32,80<br />

6 A6 London Road Bus Stop EB0118 Travis Street 7,80<br />

7 A6 London Road Traffic Signals A57(m) Mancunian Way 1,63<br />

8 A6 Downing Street Traffic Signals Grosvenor Street 0,00<br />

9 A6 Ardwick Green South Bus Stop EB3419 Ardwick Green 10,23<br />

10 A6 Ardwick Green South Signalised Pedestrian Apollo Roundabout 9,27<br />

11 A6 Ardwick Green South Roundabout Entry A6 Stockport Road 4,93<br />

12 A6 Stockport Road Signalised Pedestrian Apollo Theatre 1,20<br />

13 A6 Stockport Road Bus Stop EB0622 Apollo Theatre (OTP) 13,20<br />

14 A6 Stockport Road Bus Stop EB0625 Ardwick Post Office 19,00<br />

15 A6 Stockport Road Traffic Signals A665 Devonshire Street 35,07<br />

16 A6 Stockport Road Signalised Pedestrian Grove Village 2,80<br />

17 A6 Stockport Road Bus Stop EB0626 Devonshire Street 8,50<br />

18 A6 Stockport Road Signalised Pedestrian Winterford Avenue 0,27<br />

19 A6 Stockport Road Bus Stop EB0627 Winterford Avenue 9,50<br />

20 A6 Stockport Road Signalised Pedestrian Plymouth Grove West 1,50<br />

21 A6 Stockport Road Bus Stop EB0628 Plymouth Grove West 8,70<br />

22 A6 Stockport Road Bus Stop EB0629 Plymouth Grove 14,67<br />

23 A6 Stockport Road Traffic Signals A5184 Plymouth Grove 118,00<br />

24 A6 Stockport Road Traffic Signals A6010 Kirkmanshulme Lane 55,33<br />

25 A6 Stockport Road Signalised Pedestrian Longsight District Centre 7,77<br />

EB0631 Longsight Shopping Centre<br />

26 A6 Stockport Road Bus Stop<br />

(Stop B)<br />

35,47<br />

27 A6 Stockport Road Traffic Signals A6010 Dickenson Road 27,27<br />

28 A6 Stockport Road Traffic Signals A5079 Slade Lane 12,57<br />

29 A6 Stockport Road Bus Stop EB0447 Slade Lane (OTP) 24,80<br />

30 A6 Stockport Road Bus Stop EB0450 East Road 9,80<br />

31 A6 Stockport Road Traffic Signals Crowcroft Road 9,97<br />

32 A6 Stockport Road Bus Stop EB0356 Matthews Lane 19,00<br />

33 A6 Stockport Road Traffic Signals Matthews Lane 11,33<br />

34 A6 Stockport Road Signalised Pedestrian Mayford Avenue (Woodford Ave) 27,77<br />

35 A6 Stockport Road Bus Stop EB0358 Mayfield Road 11,13<br />

36 A6 Stockport Road Bus Stop EB0299 Carrill Grove 20,60<br />

37 A6 Stockport Road Signalised Pedestrian Cromwell Grove 49,57<br />

38 A6 Stockport Road Traffic Signals B5093 Albert Road (1st Set) 17,90<br />

Traffic Signals With<br />

39 A6 Stockport Road<br />

Pedestrian Facilities B5093 Albert Road (2nd Set)<br />

1,63<br />

40 A6 Stockport Road Bus Stop EB0360 Albert Road 15,13<br />

41 A6 Stockport Road Traffic Signals Alma Road 27,93<br />

42 A6 Stockport Road Bus Stop EB0301 Delamere Road 16,77<br />

43 A6 Stockport Road Signalised Pedestrian Crayfield Road 4,67<br />

44 A6 Stockport Road Bus Stop EB0363 Crayfield Road 7,50<br />

45 A6 Stockport Road Signalised Pedestrian Darnforth Grove (Hume St) 4,73<br />

46 A6 Stockport Road Bus Stop EB0364 Broom Lane 14,20<br />

47 A6 Stockport Road Traffic Signals B6178 Broom Lane 12,73<br />

48 A6 Stockport Road Signalised Pedestrian Cringle Road 1,77<br />

49 A6 Stockport Road Traffic Signals Lloyd Road 23,60<br />

50 A6 Wellington Road North Traffic Signals Crossley Road 1,03<br />

51 A6 Wellington Road North Bus Stop SG1282 McVities 9,90<br />

52 A6 Wellington Road North Signalised Pedestrian Weybrook Road 1,00<br />

53 A6 Wellington Road North Bus Stop SG0023 Lloyd Road (OTP) 1,63<br />

54 A6 Wellington Road North Signalised Pedestrian Millwain Drive 3,00<br />

55 A6 Wellington Road North Bus Stop SG4008 Milwain Drive 4,87<br />

56 A6 Wellington Road North Traffic Signals A626 Manchester Road 14,03<br />

57 A6 Wellington Road North Bus Stop SG4189 Manchester Road 9,57<br />

58 A6 Wellington Road North Traffic Signals B5169 School Lane (Heaton Moor Lane) 37,57<br />

| Short term Scientific Mission -ITALY 36


(1st Set)<br />

Traffic Signals With B5169 School Lane (Heaton Moor Lane)<br />

59 A6 Wellington Road North Pedestrian Facilities (2nd Set)<br />

0,00<br />

60 A6 Wellington Road North Bus Stop SG4192 Heaton Moor Road (Stop D) 11,97<br />

61 A6 Wellington Rd N Signalised Pedestrian Brackley Road (Langford Rd) 0,37<br />

62 A6 Wellington Rd North Bus Stop SG4190 Brackley Road 9,47<br />

63 A6 Wellington Rd North Signalised Pedestrian Glenfield Road (Warwick Rd) 0,27<br />

64 A6 Wellington Rd North Bus Stop SG4193 Warwick Road 3,37<br />

65 A6 Wellington Rd North Traffic Signals Heaton Road 8,37<br />

66 A6 Wellington Rd North Bus Stop SG4191 Heaton Road 6,43<br />

67 A6 Wellington Rd North Bus Stop SG4194 Belmont Bridge 4,53<br />

68 A6 Wellington Rd North Traffic Signals Belmont Way 16,63<br />

69 A6 Wellington Rd North Bus Stop SG4195 Belmont Way 7,10<br />

70 A6 Wellington Road North Traffic Signals George's Road 7,77<br />

71 A6 Wellington Road North Signalised Pedestrian Wellesley House 1,90<br />

72 A6 Wellington Road North Bus Stop SG4197 Wellesley House 2,50<br />

73 A6 Wellington Road North Traffic Signals Heaton Lane 5,97<br />

74 A6 Wellington Road South Bus Stop SG1552 Mersey Square (Stop BB) (OTP) 74,53<br />

75 A6 Wellington Road South Traffic Signals St Petersgate (Exchange St) 40,47<br />

76 A6 Wellington Road South Traffic Signals Grand Central Complex (Wellington St.) 1,23<br />

77 A6 Wellington Road South Bus Stop SG1486 Grand Central (Stop RR) 37,13<br />

78 A6 Wellington Road South Traffic Signals John Street (Railway Rd) 6,43<br />

79 A6 Wellington Road South Traffic Signals Stockport Town Hall (Edward Street) 7,47<br />

80 A6 Wellington Road South Bus Stop SG4199 Stockport College (Stop YY) 22,27<br />

81 A6 Wellington Road South Signalised Pedestrian Ratcliffe Street 2,53<br />

82 A6 Wellington Road South Signalised Pedestrian Stockport College 0,37<br />

83 A6 Wellington Road South Signalised Pedestrian Brentnall Street (Charlesworth St) 2,20<br />

84 A6 Wellington Road South Bus Stop SG1085 Brentnall Street 6,37<br />

85 A6 Wellington Road South Traffic Signals B5465 Longshut Lane 23,30<br />

86 A6 Wellington Road South Bus Stop SG4052 Longshut Lane 10,23<br />

87 A6 Wellington Road South Signalised Pedestrian Daisy Street (Wellington Gr) 3,23<br />

88 A6 Wellington Road South Traffic Signals Higher Hillgate 50,10<br />

89 A6 Buxton Road Bus Stop SG4053 Bramhall Lane (Stop B) 6,70<br />

90 A6 Buxton Road Traffic Signals B6171 Nangreave Road 16,23<br />

91 A6 Buxton Road Bus Stop SG4054 Nangreave Road (OTP) 15,43<br />

92 A6 Buxton Road Signalised Pedestrian Regent Road (Heaviley Grove) 3,80<br />

93 A6 Buxton Road Bus Stop SG4055 Kennerley Road 12,07<br />

94 A6 Buxton Road Traffic Signals Kennerley Road 15,93<br />

95 A6 Buxton Road Bus Stop SG4056 Corbar Road 6,50<br />

96 A6 Buxton Road Signalised Pedestrian Mile End Lane 4,30<br />

97 A6 Buxton Road Signalised Pedestrian Lake Street (Woodsmoor Ln) 11,97<br />

98 A6 Buxton Road Bus Stop SG4057 Woodsmoor Lane 5,57<br />

99 A6 Buxton Road Signalised Pedestrian Cherry Tree Lane (Norwood Rd) 18,27<br />

100 A6 Buxton Road Bus Stop SG4059 Cherry Tree Lane 9,93<br />

101 A6 Buxton Road Bus Stop SG4060 Dialstone Lane (Stop B) (OTP) 15,10<br />

102 A6 Buxton Road Signalised Pedestrian Bonis Crescent (Dialstone Ln) 31,23<br />

103 A6 Buxton Road Traffic Signals Dialstone Lane (Poplar Grove) 20,83<br />

104 A6 London Road Traffic Signals Sainsbury's (New Moor Lane) 30,23<br />

105 A6 London Road Bus Stop SG4061 Sainsbury's 17,87<br />

106 A6 London Road Traffic Signals Mill Street 5,17<br />

107 A6 London Road Signalised Pedestrian Vernon Street (Brewers Grn) 5,53<br />

108 A6 London Road Bus Stop SG4062 Brewers Green 7,83<br />

109 A6 London Road Traffic Signals Commercial Road 12,60<br />

110 A6 London Road Bus Stop SG4063 Commercial Road 6,60<br />

111 A6 London Road Signalised Pedestrian Vine Street (Hope St) 1,30<br />

112 A6 London Road Signalised Pedestrian Chapel Street (Hatherlow Lane) 12,33<br />

113 A6 London Road Bus Stop SG4064 Queens Road 7,80<br />

114 A6 London Rd Signalised Pedestrian Queens Road (Grundey St) 7,63<br />

115 A6 London Rd Bus Stop SG0944 Norbury Post Office 3,83<br />

116 A6 London Rd Traffic Signals Brook Street (McDonalds) 16,37<br />

117 A6 London Rd Traffic Signals A627 Torkington Road 11,13<br />

118 A6 London Rd Bus Stop SG4009 Torkington Road (Stop A) 6,53<br />

119 A6 London Rd Traffic Signals A523 Macclesfield Road 40,97<br />

120 A523 Macc. Road (Bus Layby) Bus Stop SG4302 Rising Sun (Stop D) (OTP) 0,00<br />

In direction Hazel Grove the service during the journey accumulates in average 1069,7<br />

second (17,8 minutes) on the intersections and 634,8 seconds (10,6 minutes) on the stops.<br />

| Short term Scientific Mission -ITALY 37


From these results it is possible to notice as for around the 60% of the time of general<br />

journey a middle vehicle is stationary along the line. It’s easy to understand as an<br />

improvement of the infrastructural characteristics (increasing of length of reserved lane)<br />

and of the intersections (priority to the bus) can make even more efficient and more<br />

reliable. the service on the 192 line.<br />

3.3. Reliability Indicators Valuation<br />

In this chapter are calculated some reliability indicators in relationship to the data collected<br />

during the Short Mission. The obtained indicators are founded on elaborations of data<br />

observed on one average day furnished by the GMPTE, therefore are obtained average<br />

values of service and not punctual on the single runs. In this specific case the indicators of<br />

reliability are calculated with an approach to frequency.<br />

The main indicators of reliability that it is possible to obtain considering the data collected<br />

are the Frequency Regularity and the % runs that respect the scheduled frequency.<br />

The indicator Frequency Regularity is calculated considering a parameter of base as the<br />

Average Frequency defined in the temporal slot in which has been developed the detection<br />

data by the GMPTE (rush hours):<br />

Average Frequency : AF = Runs/Time;<br />

The two indicators of reliability are so defined:<br />

Frequency Regularity (FR): standard deviation of the frequency from the average<br />

frequency;<br />

FR=[∑ i=1,..,n (x i –AF) 2 /n] 1/2<br />

where:<br />

n = number of passages;<br />

x i = punctual frequency;<br />

AF = Average frequency.<br />

| Short term Scientific Mission -ITALY 38


<strong>RELIABILITY</strong>, % of runs that respect the scheduled frequency:<br />

<strong>RELIABILITY</strong> = 1 - R F /R Tot ;<br />

where:<br />

R F = Runs that failed the scheduled frequency;<br />

R Tot = Total runs.<br />

Some data related to the main stop of the line (Mersey Square) have been obtained, that is<br />

having available the instants in which the service passes from the stop during the day (see<br />

Tab.3.7), is been possible to develop some considerations and to obtain some average<br />

values of reliability of the service during the line 192 in the considered average day for this<br />

specific stop (May 21st 2008). The application appears interesting however in terms of<br />

methodological approach and could be wide improved on other stops of line.<br />

Tab.3.7. Data of main stop of route 192 (example)<br />

Date Stop Description Service<br />

Actual<br />

Time<br />

Destination<br />

Time<br />

Period<br />

Time<br />

difference<br />

1-May-08 Mersey Square 192 07:30 PICCADILLY AM Peak<br />

21-May-08 Mersey Square 192 07:33 PICCADILLY AM Peak 3<br />

21-May-08 Mersey Square 192 07:36 PICCADILLY AM Peak 3<br />

21-May-08 Mersey Square 192 07:41 PICCADILLY AM Peak 5<br />

21-May-08 Mersey Square 192 07:43 PICCADILLY AM Peak 2<br />

21-May-08 Mersey Square 192 07:46 PICCADILLY AM Peak 3<br />

21-May-08 Mersey Square 192 07:51 PICCADILLY AM Peak 5<br />

21-May-08 Mersey Square 192 07:56 PICCADILLY AM Peak 5<br />

21-May-08 Mersey Square 192 08:00 PICCADILLY AM Peak 4<br />

21-May-08 Mersey Square 192 08:02 PICCADILLY AM Peak 2<br />

21-May-08 Mersey Square 192 08:06 PICCADILLY AM Peak 4<br />

21-May-08 Mersey Square 192 08:07 PICCADILLY AM Peak 1<br />

21-May-08 Mersey Square 192 08:13 PICCADILLY AM Peak 6<br />

21-May-08 Mersey Square 192 08:15 PICCADILLY AM Peak 2<br />

21-May-08 Mersey Square 192 08:19 PICCADILLY AM Peak 4<br />

21-May-08 Mersey Square 192 08:21 PICCADILLY AM Peak 2<br />

21-May-08 Mersey Square 192 08:35 PICCADILLY AM Peak 14<br />

21-May-08 Mersey Square 192 08:38 PICCADILLY AM Peak 3<br />

21-May-08 Mersey Square 192 08:41 PICCADILLY AM Peak 3<br />

…….. ………………. …….. ……….. …………….. ………. …………<br />

| Short term Scientific Mission -ITALY 39


The parameter Time Differences is the headway between two successive buses at the stop.<br />

Considering the data registered during the analyzed day is possible to calculate the average<br />

value of the frequency really developed for each direction. These values refer to the<br />

different peak hours, that are AM PEAK (7,30 -9,30), INTER PEAK (13,00-15,00), PM<br />

PEAK (16,00-18,30):<br />

Towards Manchester:<br />

AM PEAK - AF = Average of time differences = 1 bus every 2,34 minutes<br />

INTER PEAK - AF = Average of time differences = 1 bus every 2,55 minutes<br />

PM PEAK - AF = Average of time differences = 1 bus every 2,41 minutes<br />

Towards Hazel Grove:<br />

AM PEAK - AF = Average of time differences = 1 bus every 3,54 minutes<br />

INTER PEAK - AF = Average of time differences = 1 bus every 3,25 minutes<br />

PM PEAK - AF = Average of time differences = 1 bus every 3,50 minutes<br />

The regularity (irregularity) some frequency can be calculated in terms of standard<br />

deviation from the value of average frequency:<br />

Towards Manchester:<br />

AM PEAK - FR = Standard Deviation = 1,17 minutes<br />

INTER PEAK - FR = Standard Deviation = 1,33 minutes<br />

PM PEAK - FR = Standard Deviation = 1,97 minutes<br />

Towards Hazel Grove:<br />

AM PEAK - FR = Standard Deviation = 2,51 minutes<br />

INTER PEAK -FR = Standard Deviation = 2,74 minutes<br />

PM PEAK - FR = Standard Deviation = 3,37 minutes<br />

| Short term Scientific Mission -ITALY 40


Fig. 3.6. Standard deviation (Towards Manchester)<br />

Fig. 3.7. Standard deviation (Towards Hazel Grove)<br />

The percentage of the runs that don't respect the scheduled frequency (condition of low<br />

service), is defined by the relationship among the runs that pass on the considered stop<br />

after a greater temporal period of the value of the scheduled frequency and the total<br />

number of runs in the considered slot time. More lower it is this percentage, more higher it<br />

results the reliability of the service.<br />

Dealing with this analysis it is possible to consider the scheduled frequency (case a, which<br />

in this case is 1 bus every 10 minutes) or, alternatively, the average frequency obtained by<br />

field observations (case b). Hence on 192 line of Manchester the observed supply, in terms<br />

| Short term Scientific Mission -ITALY 41


of frequency, is largely more consistent than the one initially set or established in theory.<br />

In this second case it is possible to detect major differences in terms of service efficiency,<br />

also due to the fact that the term of comparison is sensibly lower (around 3 minutes instead<br />

of 10).<br />

However the index <strong>RELIABILITY</strong> (% runs that respect the scheduled frequency) assumes<br />

the following values:<br />

Case a(freq. 10 min)<br />

Towards Manchester:<br />

AM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 100%<br />

INTER PEAK - <strong>RELIABILITY</strong> =1 - Failed Runs/Total Runs = 100%<br />

PM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 100%<br />

Towards Hazel Grove:<br />

AM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 97%<br />

INTER PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 97,3%<br />

PM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 95,2%<br />

Case b (freq. 3min)<br />

Towards Manchester:<br />

AM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 60%<br />

INTER PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 47%<br />

PM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 61%<br />

Towards Hazel Grove:<br />

AM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 62%<br />

INTER PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 60%<br />

PM PEAK - <strong>RELIABILITY</strong> = 1 - Failed Runs/Total Runs = 65%<br />

It is possible to see how the indicators assume values remarkably higher in the second<br />

instance.<br />

A further analysis can be developed considering the average wait time on the stops that can<br />

be calculated expressed as:<br />

Tw = β / AF;<br />

in which β is a coefficient that is equal to 1 if the line is to perfectly regulate, or equal to<br />

0,5 if the line is completely casual. In this case the service is completely random.<br />

| Short term Scientific Mission -ITALY 42


Towards Manchester:<br />

AM PEAK – Average wait time = Tw = β / AF = 0,5 / AF = 1,17 minutes<br />

INTER PEAK - Average wait time = Tw = β / AF = 0,5 / AF = 1,27 minutes<br />

PM PEAK - Average wait time = Tw = β / AF = 0,5 / AF = 1,20 minutes<br />

Towards Hazel Grove:<br />

AM PEAK - Average wait time = Tw = β / AF = 0,5 / AF = 1,77 minutes<br />

INTER PEAK - Average wait time = Tw = β / AF = 0,5 / AF = 1,62 minutes<br />

PM PEAK - Average wait time = Tw = β / AF = 0,5 / AF = 1,75 minutes<br />

It is possible to deduce that with average waiting times around this measure (around 1,5<br />

minutes) the users perceive however the service as a quality service.<br />

3.4. Overview and conclusions<br />

The obtained results suggest an elevated frequency on the e 192 line (1 bus every 2,5<br />

minutes in direction Manchester, 1 bus every 3,5 minutes in direction Hazel Grove). The<br />

average waiting time on the stop considering the service as “random” is variable from 1,2<br />

minutes to 1,7 minutes; these values are limited and therefore give to the users a perception<br />

of reliable service.<br />

Considering the regularity (irregularity) indicator it is possible to notice as the regularity of<br />

the service changes according to the direction; in fact the service on the direction<br />

Manchester is more regular (standard deviation is lower). Finally, fixing the attention on<br />

the last indicator “<strong>RELIABILITY</strong>” that give as output the percentage of the runs that<br />

respect the scheduled frequency it is evident that in direction Manchester the frequency is<br />

respected on the 100% of the runs (in the considered peak hours) while in direction Hazel<br />

Grove the percentage is not 100% but is however high.<br />

From the data concerning the average delays on the different intersections along the route<br />

it results clear as an improvement of the facilities, first among the whole increasing of the<br />

kms of reserved lane, will increase the service in terms of efficiency and reliability.<br />

| Short term Scientific Mission -ITALY 43


Special thanks go to François Rambaud, Domenico Gattuso, Claire Blanchard, Pascal Lasagne which made<br />

possible my "short mission".<br />

Thanks also to all who have helped me in gathering data for research: Nick Vaughan (Department Manager<br />

– Project Development GMPTE), Melanie Watson (Department Manager – Transport Services GMPTE),<br />

Celia Hunt (Assistant to Melanie Watson), Steve Gilholme (Service Account Manager – Bus, Transport<br />

Services GMPTE), Brian Young (Senior Project Manager – Quality Bus Corridor (QBC),Transport Services<br />

GMPTE),Paul Chandler (Senior Project Manager – Quality Bus Corridor (QBC), Transport Services<br />

GMPTE), Neil Guy (Team Leader – Bus Operator Analyst, Transport Services GMPTE), Jack Ripley<br />

(Service Account Manager – Bus, Transport Services GMPTE) and all those I met on my visit in Manchester.<br />

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Siti Web<br />

[1.]www.bhls.eu<br />

[2.] www.dft.gov.uk/stellent/groups/dft_mobility<br />

[3.] www.fco.gov.uk<br />

[4.]www.tfl.gov.uk/tube/using/useful-info/safet<br />

[5.]www.academie-qualitè.com<br />

[6.] www.federtrasporti.it<br />

| Short term Scientific Mission -ITALY 47

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