Guidelines for the Preparation of Transportation Impact Studies - 8th ...

6.0 Evaluation of Transportation Impacts and Identification of
Transportation System Changes Needed to Mitigate these
Impacts
Sections 6.1 and 6.2 outline the elements of the TIS useful in identifying and evaluating the
impacts of site-generated traffic and transit demand on road and transit performance.
Transportation system and service changes and other measures required to ensure acceptable
operation of the transportation system are also identified.
6.1 Evaluation of Impacts of Site Generated Traffic Demand
6.1.1 Evaluate those signalized and unsignalized intersections which will be noticeably affected
(see 3.2.1) by site-generated traffic volumes for all relevant time periods and scenarios.
The analysis should include volume/capacity ratios, average and 95 th percentile queue
lengths, and average delay for:
• existing traffic;
• existing traffic adjusted to account for background changes; and
• existing traffic adjusted for background changes plus forecast site-generated traffic
demand after accounting for the effects of the proposed TDM plan and other
adjustments.
Provide a table or tables showing volume/capacity ratios, average and 95 th percentile queue
lengths, and average delay for all movements at all study intersections.
Discussions with Halifax Regional Municipality staff would be useful in confirming
the scope of the analysis, the suitability of alternative methods and assumptions
for performance and queuing analyses, and the potential need for supplementary
surveys or analyses.
6.1.2 Provide documentation in an appendix to the TIS of all assumptions used in the
performance analysis concerning lane configuration/use, pedestrian activity, saturation
flows, traffic signal cycle length, phasing and timing, use of the inter-green phase, and
other relevant parameters. Existing signal timings should be assumed in the performance
analysis. Signal timing modifications may be considered as a measure to address capacity
or performance deficiencies.
6.1.3 Evaluate future pedestrian activity associated with the development and related
implications for signal warrant calculations and signal timing requirements to provide
pedestrian road-crossing opportunities. Of particular interest are pedestrian connections to
transit services.
TISGUIDE8.WPD September 1, 2007 page 17