Sensys Stud Trial - Sensys Networks

Transfield Services 

Sensys Stud Trial 

Penrose Site Data Analysis 

Partners for Change


Executive Summary 

Transfield Services along with New Zealand Transport Agency undertook a trial of the 

Sensys Wireless Vehicle Detection System (Sensys studs) on Auckland’s motorway 

carriageway. 

The trial involved installing six Sensys studs at Penrose on the Southern Motorway, one pair 

on each of the three northbound lanes. These studs were connected wirelessly to an 

access point strapped to a roadside CCTV camera pole, and further connected, via network 

cables, to the two networks inside the roadside cabinet, namely the TDM Ethernet Network 

and the SCATS network. 

Data from the Sensys was collected through these two systems as part of the trial. Two 

tests were carried out: 

1. The Sensys data collected via the SCATS network was compared with traditional 

inductive loops for Occupancy and Count. The count average for these results gives 

an average difference of 2.07% while the occupancy gives an average difference of 

6.28% 

2. Manual counts have also been undertaken to verify flow data from both Sensys and 

inductive loops. The manual count showed that the Sensys counts were on average 

1.5% different than actual counts and the difference for loops was 0.5% 

Cost analysis has been undertaken showing the cost difference between inductive loops and 

Sensys studs, this was provided to the New Zealand Transport Agency by Transfield 

Services. 

Commercial in Confidence Page 2


Contents 

1. Summary of Results 4 

1.1 Summary of Results from New Zealand Tests 

1.2 Summary of Results from Australian Tests 

2. Introduction 6 

2.1 Background 

2.2 Technology Summary 

2.3 Advantages of the Technology 

3. Trial Details 8 

3.1 Trial Site 

3.2 Equipment List 

3.3 Equipment Setup 

3.4 Site Layout 

3.5 Installation of Wireless Sensor Stud 

3.6 Traffic Control 

4. Data Collection 17 

4.1 Trial Software 

4.2 Data Collection Methods 

5. Data Summary 20 

5.1 First Set of Results 

5.2 Second Set of Results 

6. Cost Comparison and Compatibility 23 

6.1 Cost Comparison Installation of Detectors 

6.2 Cost Comparison Lifetime of Detectors 

6.4 Cost Comparison for Typical Installation 

6.5 Cost Comparison, Typical Installation Including Lifecycle Costs 

7. Revision History 32 

8. Document Acceptance 32 

9. Acknowledgements 32 

Appendix B – Results from Second Test 33 

Appendix B – Results from Second Test 



1. Summary of Results 

This document details the trial that was carried out of the Sensys studs on the Auckland 

motorway system. Extensive testing has also been carried out for various agencies in 

Australia. Results of both tests are summarised below. 

It should be noted that loop data cannot be treated as true values even though loop data 

was used in this report as reference data. True values can only be established by manual 

counts 

1.1 Summary of Results from New Zealand Tests 

The testing in New Zealand occurred on 2 separate days. The 1 st test was a direct 

comparison between inductive loops and Sensys studs, while the second compared actual 

counts from a video camera with the 2 different technologies. 

When the Sensys data collected via the SCATS network was compared with traditional 

inductive loops for Occupancy and Count, the count average for these results gives an 

average difference of 2.07% while the occupancy gives an average difference of 6.28% 

When the manual counts were compared it showed that the Sensys counts were on average 

1.5% different than actual counts compared with a 0.5% difference for loops. 

From the data gathered in New Zealand we can conclude that: 

• The counts from the Sensys studs were 1% less accurate that those from inductive 

loops when compared to actual counts. 

• Occupancy data from the Studs was 6% higher than the data given by the inductive 

loops when connected to SCATS 

1.2 Summary of Results from Australian Tests 

This section summarises the testing that has already been carried out by Vic Roads, Main 

Roads WA, Department of Transport, Energy and Infrastructure SA, and Queensland 

Department of Main Roads. These tests involved 3 Stages: Stage 1 involved laboratory 

testing, Stage 2 controlled field tests and Stage 3 on-site tests 

In summary the report found that the Sensys dectector showed a performance comparable 

to that of inductive loops and should be suitable for real-time traffic applications. 

The following are excerpts for the report produced by ‘ARRB Group Ltd’: 



Stage 1 concluded that the Sensys detector is a well-designed and reliable detector under a 

wide range of environmental conditions experienced in Australian cities. Stage 2 concluded 

that, relative to inductive loops, Sensys counts were similar and that it was worthwhile to 

move on to Stage 3 on-site tests. Stage 2 further reported that the sensitivity of a vehicle 

detector making use of earth’s magnetic field is strongest at the south (or north) pole but 

decreases towards the equator. Following from the results of Stages 1 and 2, a freeway test 

site was selected near the Forster Road on- and off-ramps with the Monash Freeway in 

Mount Waverley, Melbourne. 

Stage 3 on the Monash Freeway in Melbourne compared the Sensys studs with inductive 

loops and manual counts obtained from video recording. The key findings were: 

• The data quality of occupancy and volume from the Sensys studs are comparable to 

loop data quality. The speed data was more susceptible to vehicles changing lanes 

as the data is from a pair of sensors. 

• Sensys volume data was compared to manual counts and was found to be 2% larger 

than true counts. The results are shown below: 

Traffic 

Parameters 

Mean 

Difference 

0.3 veh/min 

(Dry Days) 

Volume 0.42 

veh/min 

(Wet Days) 

Daily Levels 

Mean % 

Difference 

2% 

(Dry Days) 

3% 

(Wet Days) 

Mean 

Difference 

0.31 

veh/min 

1 min Level 

Mean % 

Difference 

Occupancy -1.20% -11% -1.10% -10% 

Speed - - 1.29 km/h 1% 

2% 

• The detection zone of the Sensys stud is smaller than that of an inductive loop 

detector due to physical size and technology used. The data analysis shows that at a 

1 minute level the ratio of Sensys occupancy to loop occupancy is 0.713 

• No significant difference was found between wet and dry days. 

• There was a strong linear relationship between 2 detectors in a lane. 

• Some sensor downtime was experienced however this was not quantified. 

. 



2. Introduction 

2.1 Background 

Inductive loops have been used as the primary method for detection vehicle presence on the 

Auckland motorway network for a number of years. While the technology is accurate and 

reliable it does come with a few disadvantages: 

• They are easily damaged by resurfacing works. 

• Installing them requires a significant cost in traffic management, and associated 

disruption to the road user. 

• The current inductive loops detector station only report back to a single system. This 

leads to the use of two different sets of loops in the road surface. 

A system that is not damaged by resurfacing, is easy to install and can communicate to both 

the ATMS and SCATS systems would be an improvement to the current arrangement. The 

Sensys studs offer all these advantages. 

2.2 Technology Summary 

The Sensys Wireless Vehicle Detection System can be used in traffic monitoring and 

management applications as a direct replacement for conventional inductive loops. Like 

inductive loops, Sensys wireless sensors can be located exactly where measurements are 

required; whether it is at a specific through lane, turn lane, or entrance or exit ramp. 

The Sensys Wireless Vehicle Detection System employs ruggedised in-pavement-mounted 

magneto-resistive sensors to detect the presence and movement of vehicles. The Sensys 

vehicle sensors are wireless, transmitting their real-time detection data via radio to a nearby 

Sensys access point that then communicates the data to a local traffic controller, to a remote 

traffic management system, or to both at once. The low-power circuitry gives an average 

battery life of a sensor is 10 years. When power is getting low a message is sent allowing 

planned replacements without outages. 

A Sensys access point can collect detection data from many Sensys wireless sensors, either 

directly from sensors within a range of approximately 45 meters (depending on the mounting 

height of the access point) or from sensors supported by one or more Sensys repeaters that 

are within a range of approximately 300 meters of the access point. 

Detection data collected by the Sensys access point can then be provided via contact 

closure interface to a roadside traffic controller or via IP (Internet Protocol) communications 

over twisted pair, coaxial cable, fibre optic cable, or wireless services to central facilities or 

via both data paths simultaneously. 



Figure 1. Typical Sensys Installation 

2.3 Advantages of the Technology 

The access point is then connected to both a QTC controller allowing communication with 

SCATS as well as the Ethernet fibre backbone allowing data to be sent to an ATMS system. 

The SCATS system collects count and occupancy data while the ATMS system can collect 

count, occupancy, speed and classification data from the studs. 

As the sensor can be installed quickly in a 100mm diameter drill hole, road user disruption 

and the traffic management costs are significantly less than a standard induction loop as the 

installation operation can be undertaken using a semi-static closure. 

These can be placed at a depth of 120mm giving 70mm of clearance from the top of each 

sensor to the surface which should allow for resurfacing of up to 50mm without damage to 

the sensor. 

Unlike side mounted radar technology the sensor is mounted in-road and is therefore not 

susceptible to shadowing due to high sided vehicles. Also the technology is not affected by 

environmental conditions such as snow, fog or rain which affect most video detection 

systems. 

As the sensors are wireless the amount of ducting required along the motorway is greatly 

reduced. 



3. Trial Details 

3.1 Trial Site 

The Penrose Travel Demand management (TDM) loop site has been chosen for this trial 

because it has a signal controller that is currently connected to inductive loops allowing a 

comparison with the contact closure outputs from the Sensys system. There is also an 

Ethernet switch present for connection back at the central system to output the speed, 

occupancy, classification and count data. 

The site also has an existing pole for the access point, cabinet for the contact closure rack 

and has good access from the motorway with a parking area behind barriers. 

3.2 Equipment List 

The following equipment was used for the trial: 

Item 

Qty 

Sensys AP240 Wireless Access Point 1 

Sensys VSN240 Wireless Sensors 6 

Sensys CC Master Contact Closure Card (4 Outputs) 1 

Sensys EX Expansion Contact Closure Card (4 Outputs) 1 

Sensys Access Box 1 

Traffic Controller (Type 170, NEMA TS1, NEMA TS2, or Type 2070) 1 

Software to be Installed at Traffic Centre 1 

Fixings for Access Point and Traffic Controller 

As required 

8 Core Feeder Cable (Contact Cards to Signal Controller) 30m Approx 

Cat 6 Cable (Between Wireless Access Point and Access Box) 

Cat 6 Cable (Between Access Box and Contact Closure Card) 

Cat 6 Cable (Between Master Contact Card and Expansion) 

Cat 6 Cable (Between Access Box and Ethernet Switch) 

External Conduit for Cables as Required 

Miscellaneous fixings, looms and cable ties as required 

30m Approx 

1m 

1m 

1m 

30m Approx 

As required 



3.3 Equipment Setup 

The system design is based on the TDM design for the Penrose Road mainline loop site. 

The SCATSCOM, Ethernet switch and signal controller was already installed as per the 

TDM detailed communications design. 

The changes to the original design are as follows: 

• The addition of 6 external loop connections to the controller from the contact closure 

rack. 

• A change to the CIS (Controller Information Sheet) to accommodate the connection 

of the 6 additional external loops. 

• A change to the personality to accommodate the connection of the 6 additional 

external loops. 

• A change to SCATS to accommodate a connection of the 3 additional external loops. 

(only one stud on each of the three lanes connected) 

• The addition of 6 Sensys Wireless Vehicle Detectors. 

• The addition of a Sensys Wireless Access Point. 

• The addition of a mounting rack containing 2 contact closure cards. 

• Additional connections as required. 

Please refer to ‘Figure 2. Schematic representation of the layout for Penrose Count Site 

including Sensys Studs’ 



Figure 2. Schematic representation of the layout for Penrose Count Site including 

Sensys Studs 



3.4 Site Layout 

Sensys Studs 

6 Sensys wireless vehicle detectors were installed in the road, 2 per lane approx 3.4m apart. 

These were placed approx 1m South of the existing inductance loops to minimise the 

chance of cars changing lanes between the detectors. 

Figure 3. Sensys Installation Points 

Access Point 

The Access Point was installed on a locally situated CCTV Pole at a height of approximately 

7m above the roadway surface. 

Figure 4. Access Point Installation 



Contact Closure Card 

The Contact Closure Card was installed in the existing TDM Signal Controller Cabinet and 

connected to the external inputs of the QTC Signal Controller. 

Figure 5. Contact Closure Rack in Signal Controller Cabinet 

A CAT 5 cable was installed between the Contact Closure Card and the existing TDM 

network switch. A second CAT 5 cable was installed between the Access Point and the 

Access box which provided power and data to the Access Point. 



3.5 Installation of Wireless Sensor Stud 

The studs were installed in a 102mm diameter, 120mm deep hole using a coring drill. This 

process is detailed on the following pages. 

Figure 6. Typical Sensys Installation 

1. A semi-static closure was installed according to COPTTM to close 2 lanes of the 

carriageway. 



2. Four 102mm diameter, 120mm deep holes were cored in the roadway. 

3. The hole were dried to remove excess moisture. 

4. Any loose dust was removed and 3.2mm (approx) of epoxy was added to each hole. 



5. The sensor will was placed flat in the centre of the hole with the arrow pointing in the 

direction of traffic. 

6. The holes were then filled with epoxy up to a level 20mm above the sensor. 

7. The filler material ‘EZ Street Cold Asphalt’ was then used to fill the remainder of the 

hole which was then compacted to road level. 

8. The closure was then removed. The whole operation for four studs in 2 lanes took 

less than 1 hour. Another semi-static closure was then installed in the 3 rd lane to 

install the remaining studs. 



3.6 Traffic Control 

For a 3 (or more) lane carriageway as the time taken to install each stud is less than 15 

minutes, a semi static closure can be used to close 2 lanes allowing 4 studs to be installed. 

This is considerably less time consuming than setting out a Standard 2 lane closure as is 

required to cut loops; these take longer than an hour to cut. 

Figure 7. Generic Semi-Static 2 Lane Closure 

If multiple sites are being installed then this closure can easily be moved along the motorway 

to the next site. 

For 2 lane carriageways it is considerably easier to install Sensys studs rather than inductive 

loops. When installing loops which must be installed 700mm from the edgeline, the whole 

carriageway must be closed so that the 1m safety zone can be maintained. This causes 

considerable inconvenience to road users as they have to follow detour routes. It is also 

expensive when compared to a semi-static closure, approximately $6,000 for the full closure 

compared to $600 for semi-static. 

When installing studs, as they are placed in the centre of the lane 1.5m from the edgeline, a 

single lane semi-static can be used. Similarly to a 2 lane closure, if multiple sites are being 

installed then this closure can then be easily moved along the motorway to the next site. 



4. Data Collection 

4.1 Trial Software 

The trial data was collected from 3 sources for comparison: 

• SENSYS SCATS: Data collected by SCATS through contact closures connected to the 

Sensys Access Point. 

• INDUCTANCE SCATS: Data collected by SCATS through existing inductance loops 

over TDM Network. 

• SENSYS ATMS: Data collected by TrafficDot software connected to the Sensys Access 

Point. 

SCATS 

The personality in the signal controller was altered to allow the connection of the Sensys studs 

as external inputs in addition to the inductive loops. The site was also updated in SCATS as 

shown in Fig. 8 below and allow the collection of data from both the Sensys studs and inductive 

loops. 

Figure 8. SCATS graphic showing Sensys Studs 



TrafficDot 

TrafficDot software is supplied by Sensys Networks and can be used to setup, monitor and 

maintain both Access Points and Sensys Studs. 

By installing the TrafficDot software on to one of the servers at ATTOMS it was possible to 

collect data from the 6 Sensys studs. 

Figure 9 TMC-DVTel server 1 at ATTOMS showing TrafficDot running 



4.2 Data Collection Methods 

SCATS 

Data was collected from SCATS as a comparison between Inductance Loops already installed 

under the TDM project and the Sensys studs. The Sensys Studs were installed in the road a 

few metres before the inductance loops to minimise the possibility of variations between the two 

detection systems. By collecting data in SCATS a direct comparison of the performance of the 

inductive loops vs. Sensys studs could be made in a real world environment. 

SCATS data was collected every 30 seconds over a 24hr period and an analysis was made for 

Peak traffic times and Off Peak traffic times for Friday 4 th July 2008. 

Using the SCATS connection the following data was compared between the Inductance Loops 

and Sensys Studs 

• Occupancy 

• Count 

The data for the Occupancy analysis can be found in Appendix 3. 

TrafficDot 

For the first week of the trial the TrafficDot software was left to run and collect data. (Note: The 

inductance loop for lane one at this time was not connected as it had been milled out by 

external parties) 

The Occupancy data collected for period 19/06/2008 – 27/06/2008 is shown in Appendix 1. 

By installing 2 sensors per lane TrafficDot was able to produce the average speed readings for 

each lane. 

The average speed data collected for period 19/06/2008 – 27/06/2008 is shown Appendix 2. 



5. Data Summary 

Data was collected on 2 separate occasions: 

The 1 st tests were a direct comparison between inductive loops and the Sensys studs carried 

out over a period of 17 hours. It should be noted that in this case even though the inductive 

loops were taken as the control, they cannot be assumed to be the ‘actual’ or ‘accurate’ 

The 2 nd tests compared inductive loops to Sensys studs using manual counts carried for a 

period of 2 hours over 2 days. These tests allowed a direct comparison between the 

technologies and actual counts. 



5.1 First Set of Results 

Count and Occupancy data was collected and compared on SCATS between the Induction 

Loops and the Sensys studs for the following peak and off peak times, the results are shown on 

the following 2 pages. 

07:00 – 09:00 (Peak AM) 4 th July 

11:30 – 13:30 (Off Peak AM) 4 th July 

15:30 – 17:30 (Peak PM) 4 th July 

22:30 – 00:00 (Off Peak PM) 4 th July 

The detail from these tests can be found in Appendix A 

Analysis 

The count for the morning peak (07:00 – 09:00 ) showed strange results for the count data. The 

counts recorded by both the inductive loops and Sensys studs were far below what would be 

expected for this time of day and therefore it was concluded that there was either an error with 

SCATS or the data collection during this time period, therefore these results have been 

discounted. 

The count average for these results gives a difference of 2.07% 

Time Period Difference % Difference 

11.30 - 13.30 -195 2.22% 

15.30 - 17.30 -120 1.20% 

22.30 - 00.00 -53 2.80% 

Average 2.07% 

The occupancy average for these results gives a difference of 6.28% 

Time Period Difference in % % Difference 

11.30 - 13.30 0.79 7.16% 

15.30 - 17.30 1.13 6.10% 

22.30 - 00.00 0.16 5.59% 

Average 6.28% 



5.2 Second Set of Results 

Count data was collected and compared on SCATS between the Induction Loops and the 

Sensys studs for the following times. The results were also compared with manual counts for 

the same period. 

07:30 – 07:55 8 th September 

08:40 – 9:15 8 th September 

11:56 – 13:30 12 th September 

The detail from these tests can be found in Appendix B 

Analysis Summary 

As can be seen from the results below the Sensys counts were on average 1.5% different than 

actual counts compared with a 0.5% difference for loops. 

Manual vs Loop % 

Difference 

Manual vs 

Sensys % 

Difference 

Lane 1 0.89% 1.70% 

Lane 2 0.42% -2.29% 

Lane 3 -0.28% -0.59% 

Average* 0.53% 1.52% 

* The absolute value was taken to work out the average 



6. Cost Comparison and Compatibility 

6.1 Cost Comparison Installation of Detectors 

Being an active sensor with electronic components each individual stud costs considerably 

more than a loop to supply and install, however savings can be made on traffic control. 

3 Lanes 

The first example shows a typical installation of a 3 lane site. Due to restriction in working no 

closer than 1m from cones, a full motorway closure is required to cut the loops. In this case the 

cost of supply and installation of Sensys studs is actually less that installing loops. 

For 1 Site, 3 lanes 

Stud Installation Cost Qty Total Notes 

Stud Supply $ 966.67 6 $ 5,800.02 

2 Studs required per lane to 

produce speed 

Installation $ 200.00 6 $ 1,200.00 

Traffic Management $ 300.00 1.5 $ 450.00 

Semi static @ $300 per hour. 

Assume 15 mins per stud 

$ 7,450.02 

Loop Installation 

Loop Supply and 

Install 

$ 550.00 3 $ 1,650.00 

Traffic Management $ 6,440.00 1 $ 6,440.00 

Typical motorway closure cost, 

1 on-ramp 

$ 8,090.00 

4 Lanes 

This example shows a typical installation of a 4 lane site. Here a motorway lane closure can be 

used and the safety distances maintained. This shows that it is cheaper to install loops. It 

should be noted however that cutting these 4 loops would take all night, however installing the 

studs would take just 2 hours allowing another site to be done in the same night. 





produce speed 

Installation $ 200.00 8 $ 1,600.00 

Traffic Management $ 300.00 2 $ 600.00 



$ 9,933.36 



Install 

$ 550.00 4 $ 2,200.00 



1 on-ramp 

$ 5,450.00 



3 Lanes, 2 Sites 

This example shows a typical installation of two 3 lane sites on the same side of the motorway 

in close proximity. Due to restriction in working no closer than 1m from cones, a full motorway 

closure is required to cut the loops 





produce speed 

Installation $ 200.00 12 $ 2,400.00 

Traffic Management $ 300.00 3 $ 900.00 



$ 14,900.04 



6 studs can be cut per night per 

$ 550.00 6 $ 3,300.00 

Install 

crew for closure 


$ 9,740.00 


1 on-ramp 


This example shows a typical installation of two 4 lane sites in close proximity. Here a motorway 

lane closure can be used and the safety distances maintained. 





produce speed 

Installation $ 200.00 16 $ 3,200.00 

Traffic Management $ 300.00 4 $ 1,200.00 



$ 19,866.72 



4 loops cut per night due to lane 

$ 550.00 8 $ 4,400.00 

Install 

closure complications. 

Traffic Management $ 3,250.00 2 $ 6,500.00 2 Nights Required 

$ 10,900.00 

Summary 

As can be seen from the examples above the relative costs depend heavily on the situation. 

Where there is space to close lanes to cut loops these provide a cheaper solution, whereas if 

the motorway has need to be closed due to space restrictions then studs become a more 

closely priced or even cheaper option. 



6.2 Cost Comparison Lifetime of Detectors 

Due to resealing and general determination of carriageways it is estimated that during the 10 

year lifetime of a Sensys stud the loops will have to be replaced once. This means that the cost 

of loops can be doubled for the same period of time. Therefore the 10 year lifetime costs can be 

estimated to be. 

3 Lanes 

Sensys $7,450.02 

Loops $16,180.00 

4 Lanes 


Loops $10,900.00 



Loops $19,480.00 



Loops $21,800.00 

It should be noted that these costs do not take into account the downtime and inconvenience for 

the time that the loops are milled out. As loops cannot be recut the same night as sealing, 

typically the loops are down for between 2 to 4 weeks depending on the sealing and line 

marking programme. 

As the studs send information about their battery life, they will indicate when the battery is 

getting to a low level and therefore a planned replacement schedule can be arranged. This will 

result in minimal downtime. 

Summary 

Once the full 10 year lifecycle costs are taken into account, the studs also become a cheaper 

option than loops in all situations. It may be that not all loops are required to be replaced in the 

10 year cycle, however the pricing on average will be comparable. 



6.3 Cost Comparison for Hardware 

The previous section deals with the installation of loops. Here we investigate the cost of 

installing the hardware for a typical ATMS detector station. It is assumed that that all the 

necessary communications infrastructure is in place, including an Ethernet switch for the 

detector hardware to connect to. 

The comparison is made between an Ethernet enabled Golden River traffic detector with 16 

inputs, (enough for 8 lanes) and a Sensys detector. 

Inductive Loop Detector 

Part no. Description Price per unit Notes 

GR7720 M720 unit, 16 loop, 128 MB $ 10,006.93 

memory 

Can connect up to 8 lanes 

GR7712 Connection lead, 16 loop with 

blade terminals 

$ 402.13 

GR7730 Ethernet card $ 278.40 

$ 10,687.47 

Sensys Stud Detector 

Part no. Description Price per unit Notes 

AP240-ES 

Sensys AP240 Wireless Access 

Point (up to 48 sensors) $ 6,178.93 Serial and Ethernet version 

AP240- Fixings for Access Point and 

MTG Repeaters $ 371.20 

AP240-E- 

POE 

RP240-B 

AP240- 

MTG 

Power supply + PoE Injector 

(AP240-E-48PS) $ 371.20 

Cat 6 Cable (Between Wireless 

Access Point and Access Box 

30m) $ 100.00 

Repeater (including 171 A/h 

battery pack for 10 yr operation) $3,085.60 

Fixings for Access Point and 

Repeaters $ 371.20 

$ 10,478.13 

May not be required 

depending on site layout 

Summary 

As can be seen, the hardware costs are comparable between the 2 detection systems. 



6.4 Cost Comparison for Typical Installation 

6 Lanes Spread Over 2 Carriageways 

In this example a site such as Penrose with 2 carriageways and 3 lanes per carriageway. It is 

assumed that that all the necessary communications infrastructure is in place, including an 

Ethernet switch for the detector hardware to connect to. 


It is assumed that there is sufficient space in the existing communications cabinet to house the 

loop detector. 

Description Cost Qty Total Note 

Install loops 3 lanes $ 8,090.00 2 $ 16,180.00 Detail found in section 5.1 

Cut NB tails across 

carridgeway $ 522.00 1 $ 522.00 

Hardware Supply $ 10,478.13 1 $ 10,678.47 Detail found in section 5.3 

Install Hardware in Existing 

Cabinet $ 87.00 4 $ 348.00 2 techs 2 hours 

Install tody $ 127.00 2 $ 254.00 

1 in centre island, 1 by 

cabinet 

Trench from toby to cabinet $ 58.00 10 $ 580.00 

Assume cabinet 10m from 

toby 

Cable from toby to cabinet $ 21.00 15 $ 315.00 Extra 5m for slack 

Connect and test $ 87.00 6 $ 522.00 2 techs 3 hours 

$ 29,399.47 

Sensys Detector 


Install studs 3 lanes $ 7,450.02 2 $ 14,900.04 Detail found in section 5.1 


Install Accesspoint and Cable $ 87.00 4 $ 348.00 2 techs 2 hours 

Semistatic to install Access 

Point $ 300.00 2 $ 600.00 

Install Repeater $ 87.00 2 $ 174.00 2 techs 1 hours 

Semistatic to install repeater $ 300.00 1 $ 300.00 

Trench from pole to cabinet $ 58.00 10 $ 580.00 Assume cabinet 10m from toby 


$ 27,902.17 




In this example a site such as Penrose with 2 carriageways and 4 lanes per carriageway. It is 

assumed that that all the necessary communications infrastructure is in place, including an 

Ethernet switch for the detector hardware to connect to. 


It is assumed that there is sufficient space in the existing communications cabinet to house the 

loop detector. 




carridgeway $ 522.00 1 $ 522.00 




Install tody $ 127.00 2 $ 254.00 1 in centre island, 1 by cabinet 

Trench from toby to cabinet $ 58.00 10 $ 580.00 Assume cabinet 10m from toby 



$ 24,224.47 







Point $ 300.00 2 $ 600.00 


Semistatic to install repeater $ 300.00 1 $ 300.00 



$ 32,868.85 

Summary 

As can be seen from the examples above the relative costs depend on the layout of the lanes 

as to what the technology cost would be. 



2 sites of 8 Lanes Spread Over 2 Carriageways 

In this instance 2 sites which are 500m apart will be considered. An example of where this 

would be required is for Traveller Information System. This site would consist of a central 

controller with the loop sites 250m away on either side. 


A the detector is 16 channel, 2 detectors are required to build this solution. It is assumed that 

there is sufficient space in an existing communications cabinet to house both loop detectors. 




carridgeway $ 522.00 2 $ 1,044.00 





Trench from toby to cabinet $ 58.00 500 $ 29,000.00 Assume cabinet 10m from toby 

Cable from toby to cabinet $ 28.00 510 $ 14,280.00 Extra 5m for slack each end 

Connect and test $ 87.00 12 $ 1,044.00 2 techs 6 hours 

$ 89,154.26 


It is assumed that there are lighting columns available for the repeaters and acess point to be 

connected to. 




Additional Repeaters $ 3,085.60 3 $ 10,478.13 3 additional repeaters required 

Fixings for Repeaters $ 371.20 3 $ 10,478.13 3 additional repeaters required 



Point $ 300.00 2 $ 600.00 


Semistatic to install repeater $ 300.00 4 $ 1,200.00 4 Repeaters 



$ 75,287.83 

Summary 

In a situation of multiple sites in close proximity there is a significant advantage in using Sensys 

as it is a wireless technology. It should also be noted that for the inductive loops it has been 

assumed that trenching along the road is possible, this may not be possible in all locations. 



6.5 Cost Comparison, Typical Installation Including Lifecycle 

Costs 

Due to resealing and general determination of carriageways it is estimated that during the 10 

year lifetime of a Sensys stud the loops will have to be replaced once. This means that the cost 

of loops can be doubled for the same period of time. Therefore the 10 year lifetime costs can be 

estimated to be. 


Sensys $27,902.17 as previously calculated 

Loops $45,579.47 as shown below 




carridgeway $ 522.00 1 $ 522.00 








$ 45,579.47 


Sensys $32,868.85 as previously calculated 

Loops $35,124.47 as shown below 




carridgeway $ 522.00 1 $ 522.00 








$ 35,124.47 



2 sites of 8 Lanes Spread Over 2 Carriageways 


Loops $110,954.26 




carridgeway $ 522.00 2 $ 1,044.00 





Trench from toby to cabinet $ 58.00 500 $ 29,000.00 Assume cabinet 10m from toby 

Cable from toby to cabinet $ 28.00 510 $ 14,280.00 Extra 5m for slack each end 

Connect and test $ 87.00 12 $ 1,044.00 2 techs 6 hours 

$ 110,954.26 

Summary 

Once the full 10 year lifecycle costs are taken into account, the studs are a cheaper option than 

loops in all situations. It may be that not all loops are required to be replaced in the 10 year 

cycle, however the pricing on average will be comparable. 



7. Revision History 

Version Changes/Comments Changed By Date 

1.1 Document Creation PR 

1.2 Revision and detail added IL 10/10 

8. Document Acceptance 

Action Name Signed Date 

Prepared by 

Ian Leach 

Reviewed by 

Paul Rendle 

Approved by 

Ian Leach 

9. Acknowledgements 

Transfield Services would like to acknowledge and thank the following people for there help and 

input for this trial. 

Vincent Lin – NZTA (Project Sponsor) 

Leon Wee – NZTA (Data Evaluation) 

Michael Daley – NZTA (Data Collection) 

Hanford Chung – Resolve Group (Data Collection) 

Central Weighing Australia – Denis and Jamie Mann (Supplier and Tech Support) 

Transfield Services Telco Division (IP setup and Installation) 

McAllister Cartage Ltd (Stud Installation) 



Appendix A – Results from First Test 

Count 

The average counts for these times over all 3 lanes are shown below. 

07:00 – 09:00 

Inductance Sensys Difference % Difference 

Lane 1 971 1102 131 13% 

Lane 2 892 1010 118 13% 

Lane 3 1177 1379 202 17% 

All Lanes 3040 3491 451 15% 

NB: These results have been discounted as the numbers are far too low for this time period so 

there was an error with either SCATS or the data collection. 

11:30 – 13:30 


Lane 1 2754 2724 -30 1.10% 

Lane 2 3050 2957 -93 3.15% 

Lane 3 3187 3115 -72 2.31% 

All Lanes 8991 8796 -195 2.22% 

15:30 – 17:30 


Lane 1 3235 3206 -29 0.90% 

Lane 2 3300 3248 -52 1.60% 

Lane 3 3600 3561 -39 1.10% 

All Lanes 10135 10015 -120 1.20% 

22:30 – 00:00 


Lane 1 608 598 -10 1.67% 

Lane 2 885 850 -35 4.12% 

Lane 3 452 444 -8 1.80% 

All Lanes 1945 1892 -53 2.80% 



Occupancy 

The average occupancy for these times over all 3 lanes are shown below. 

07:00 – 09:00 

Inductance Sensys Difference 

Lane 1 15.26% 14.90% 0.36 

Lane 2 14.18% 15.53% 1.35 

Lane 3 11.50% 9.74% 1.76 

NB: These results have been discounted as the countss are far too low for this time period so 

there was an error with either SCATS or the data collection. 

11:30 – 13:30 


Lane 1 3.44% 3.74% 0.3 8.02% 

Lane 2 3.67% 3.97% 0.3 7.56% 

Lane 3 3.03% 3.22% 0.19 5.90% 

15:30 – 17:30 


Lane 1 5.63% 5.94% 0.31 5.22% 

Lane 2 5.72% 6.07% 0.35 5.77% 

Lane 3 5.96% 6.43% 0.47 7.31% 

22:30 – 00:00 


Lane 1 0.88% 0.94% 0.06 6.38% 

Lane 2 1.13% 1.21% 0.08 6.61% 

Lane 3 0.51% 0.53% 0.02 3.77% 



Appendix B – Results from Second Test 

Sensys Data Analysis - Lane 1 

Lane 1 

Actual Difference (+, % Difference (+, higher 

Vid SCATS Manual Loop Sensys 

Manual vs 

Loop 

Manual vs 

Sensys 

Manual vs 

Loop 

Manual vs 


8/09/20087:30:10 – 7:35:10 7:30:00 – 7:35:00 151 150 145 -1 -6 -0.66% -3.97% 

8/09/20087:35:10 – 7:40:10 7:35:00 – 7:40:00 152 154 155 2 3 1.32% 1.97% 

8/09/20087:40:10 – 7:45:10 7:40:00 – 7:45:00 130 137 139 7 9 5.38% 6.92% 

8/09/20087:45:10 – 7:50:10 7:45:00 – 7:50:00 143 142 143 -1 0 -0.70% 0.00% 

8/09/20087:50:10 – 7:55:10 7:50:00 – 7:55:00 132 129 137 -3 5 -2.27% 3.79% 

8/09/20088:40:10 – 8:45:10 8:40:00 – 8:45:00 119 132 131 13 12 10.92% 10.08% 

8/09/20088:45:10 – 8:50:10 8:45:00 – 8:50:00 111 106 111 -5 0 -4.50% 0.00% 

8/09/20088:50:10 – 8:55:10 8:50:00 – 8:55:00 112 113 116 1 4 0.89% 3.57% 

8/09/20088:55:10 – 9:00:10 8:55:00 – 9:00:00 105 110 116 5 11 4.76% 10.48% 

8/09/20089:00:10 – 9:05:10 9:00:00 – 9:05:00 122 120 123 -2 1 -1.64% 0.82% 

8/09/20089:05:10 – 9:10:10 9:05:00 – 9:10:00 97 98 101 1 4 1.03% 4.12% 

8/09/20089:10:10 – 9:15:10 9:10:00 – 9:15:00 115 114 118 -1 3 -0.87% 2.61% 

12/09/200811:56:49 – 12:01:49 11:56:30 – 12:01:30 146 147 145 1 -1 0.68% -0.68% 

12/09/200812:02:49 – 12:07:49 12:02:30 – 12:07:30 136 138 135 2 -1 1.47% -0.74% 

12/09/200812:07:49 – 12:12:49 12:07:30 – 12:12:30 127 116 117 -11 -10 -8.66% -7.87% 

12/09/200812:12:49 – 12:17:49 12:12:30 – 12:17:30 133 136 134 3 1 2.26% 0.75% 

12/09/200812:17:49 – 12:22:49 12:17:30 – 12:22:30 151 148 149 -3 -2 -1.99% -1.32% 

12/09/200812:22:49 – 12:27:49 12:22:30 – 12:27:30 157 159 157 2 0 1.27% 0.00% 

12/09/200812:27:49 – 12:32:49 12:27:30 – 12:32:30 126 138 135 12 9 9.52% 7.14% 

Total 2465 2487 2507 22 42 0.89% 1.70% 

SH1 Penrose Count Actual Count Data Comparison (Lane 1) 

5-minute count 

180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

7:30:00 – 7:35:00 

7:35:00 – 7:40:00 

7:40:00 – 7:45:00 

7:45:00 – 7:50:00 

7:50:00 – 7:55:00 

8:40:00 – 8:45:00 

8:45:00 – 8:50:00 

8:50:00 – 8:55:00 

8:55:00 – 9:00:00 

9:00:00 – 9:05:00 

9:05:00 – 9:10:00 

9:10:00 – 9:15:00 

11:56:30 – 12:01:30 

12:02:30 – 12:07:30 

12:07:30 – 12:12:30 

12:12:30 – 12:17:30 

12:17:30 – 12:22:30 

12:22:30 – 12:27:30 

12:27:30 – 12:32:30 

Manual 

Loop 





Lane 2 



Manual vs 

Loop 

Manual vs 


Manual vs 

Loop 

Manual vs 


8/09/20087:30:10 – 7:35:10 7:30:00 – 7:35:00 137 142 139 5 2 3.65% 1.46% 

8/09/20087:35:10 – 7:40:10 7:35:00 – 7:40:00 136 136 132 0 -4 0.00% -2.94% 

8/09/20087:40:10 – 7:45:10 7:40:00 – 7:45:00 126 133 130 7 4 5.56% 3.17% 

8/09/20087:45:10 – 7:50:10 7:45:00 – 7:50:00 128 122 117 -6 -11 -4.69% -8.59% 

8/09/20087:50:10 – 7:55:10 7:50:00 – 7:55:00 127 132 132 5 5 3.94% 3.94% 

8/09/20088:40:10 – 8:45:10 8:40:00 – 8:45:00 111 108 105 -3 -6 -2.70% -5.41% 

8/09/20088:45:10 – 8:50:10 8:45:00 – 8:50:00 107 110 102 3 -5 2.80% -4.67% 

8/09/20088:50:10 – 8:55:10 8:50:00 – 8:55:00 92 94 97 2 5 2.17% 5.43% 

8/09/20088:55:10 – 9:00:10 8:55:00 – 9:00:00 105 100 103 -5 -2 -4.76% -1.90% 

8/09/20089:00:10 – 9:05:10 9:00:00 – 9:05:00 110 111 113 1 3 0.91% 2.73% 

8/09/20089:05:10 – 9:10:10 9:05:00 – 9:10:00 94 96 99 2 5 2.13% 5.32% 

8/09/20089:10:10 – 9:15:10 9:10:00 – 9:15:00 114 111 109 -3 -5 -2.63% -4.39% 

12/09/200811:56:49 – 12:01:49 11:56:30 – 12:01:30 141 147 142 6 1 4.26% 0.71% 

12/09/200812:02:49 – 12:07:49 12:02:30 – 12:07:30 144 141 138 -3 -6 -2.08% -4.17% 

12/09/200812:07:49 – 12:12:49 12:07:30 – 12:12:30 154 157 150 3 -4 1.95% -2.60% 

12/09/200812:12:49 – 12:17:49 12:12:30 – 12:17:30 139 140 137 1 -2 0.72% -1.44% 

12/09/200812:17:49 – 12:22:49 12:17:30 – 12:22:30 164 161 152 -3 -12 -1.83% -7.32% 

12/09/200812:22:49 – 12:27:49 12:22:30 – 12:27:30 136 134 123 -2 -13 -1.47% -9.56% 

12/09/200812:27:49 – 12:32:49 12:27:30 – 12:32:30 139 139 129 0 -10 0.00% -7.19% 

Total 2404 2414 2349 10 -55 0.42% -2.29% 



180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

7:30:00 – 7:35:00 

7:35:00 – 7:40:00 

7:40:00 – 7:45:00 

7:45:00 – 7:50:00 

7:50:00 – 7:55:00 

8:40:00 – 8:45:00 

8:45:00 – 8:50:00 

8:50:00 – 8:55:00 

8:55:00 – 9:00:00 

9:00:00 – 9:05:00 

9:05:00 – 9:10:00 

9:10:00 – 9:15:00 

11:56:30 – 12:01:30 

12:02:30 – 12:07:30 

12:07:30 – 12:12:30 

12:12:30 – 12:17:30 

12:17:30 – 12:22:30 

12:22:30 – 12:27:30 

12:27:30 – 12:32:30 

Manual 

Loop 





Lane 3 



Manual vs 

Loop 

Manual vs 


Manual vs 

Loop 

Manual vs 


8/09/20087:30:10 – 7:35:10 7:30:00 – 7:35:00 141 145 143 4 2 2.84% 1.42% 

8/09/20087:35:10 – 7:40:10 7:35:00 – 7:40:00 147 144 145 -3 -2 -2.04% -1.36% 

8/09/20087:40:10 – 7:45:10 7:40:00 – 7:45:00 133 131 130 -2 -3 -1.50% -2.26% 

8/09/20087:45:10 – 7:50:10 7:45:00 – 7:50:00 124 130 133 6 9 4.84% 7.26% 

8/09/20087:50:10 – 7:55:10 7:50:00 – 7:55:00 135 128 133 -7 -2 -5.19% -1.48% 

8/09/20088:40:10 – 8:45:10 8:40:00 – 8:45:00 112 118 116 6 4 5.36% 3.57% 

8/09/20088:45:10 – 8:50:10 8:45:00 – 8:50:00 101 98 100 -3 -1 -2.97% -0.99% 

8/09/20088:50:10 – 8:55:10 8:50:00 – 8:55:00 115 114 113 -1 -2 -0.87% -1.74% 

8/09/20088:55:10 – 9:00:10 8:55:00 – 9:00:00 109 109 109 0 0 0.00% 0.00% 

8/09/20089:00:10 – 9:05:10 9:00:00 – 9:05:00 123 122 127 -1 4 -0.81% 3.25% 

8/09/20089:05:10 – 9:10:10 9:05:00 – 9:10:00 90 94 104 4 14 4.44% 15.56% 

8/09/20089:10:10 – 9:15:10 9:10:00 – 9:15:00 123 115 116 -8 -7 -6.50% -5.69% 

12/09/200811:56:49 – 12:01:49 11:56:30 – 12:01:30 161 163 159 2 -2 1.24% -1.24% 

12/09/200812:02:49 – 12:07:49 12:02:30 – 12:07:30 160 162 159 2 -1 1.25% -0.63% 

12/09/200812:07:49 – 12:12:49 12:07:30 – 12:12:30 151 146 140 -5 -11 -3.31% -7.28% 

12/09/200812:12:49 – 12:17:49 12:12:30 – 12:17:30 165 162 159 -3 -6 -1.82% -3.64% 

12/09/200812:17:49 – 12:22:49 12:17:30 – 12:22:30 157 164 159 7 2 4.46% 1.27% 

12/09/200812:22:49 – 12:27:49 12:22:30 – 12:27:30 143 139 135 -4 -8 -2.80% -5.59% 

12/09/200812:27:49 – 12:32:49 12:27:30 – 12:32:30 154 153 149 -1 -5 -0.65% -3.25% 

Total 2544 2537 2529 -7 -15 -0.28% -0.59% 



180 

160 

140 

120 

100 

80 

60 

40 

20 

0 

7:30:00 – 7:35:00 

7:35:00 – 7:40:00 

7:40:00 – 7:45:00 

7:45:00 – 7:50:00 

7:50:00 – 7:55:00 

8:40:00 – 8:45:00 

8:45:00 – 8:50:00 

8:50:00 – 8:55:00 

8:55:00 – 9:00:00 

9:00:00 – 9:05:00 

9:05:00 – 9:10:00 

9:10:00 – 9:15:00 

11:56:30 – 12:01:30 

12:02:30 – 12:07:30 

12:07:30 – 12:12:30 

12:12:30 – 12:17:30 

12:17:30 – 12:22:30 

12:22:30 – 12:27:30 

12:27:30 – 12:32:30 

Manual 

Loop

Sensys Stud Trial - Sensys Networks

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