787 COHOES BOULEVARD PLAN PROJECT OUTCOMES


in 2019 the New York State Department of Transportation installed raised pavement at the intersection of Route 787 and Dyke Road as part of an overhaul of the busy highway. The work was part of a $15 million project to convert Route 787 — also known as Cohoes Boulevard — into a pedestrian-friendly gateway.

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AN AVERAGE DAY BEFORE AND AFTER


Before the Project (2016-2018)

The time it took to traverse this corridor was 2 minutes and 47 seconds and the average hours of day per day was 54.88 hours, most of which occurred during evening rush hour on the northbound side of the road. The dark orange line in the graph on the left depicts the hours of delay by time of day across an average day. The purple line is the average hours of delay from 2016-2023 and the line yellow depicts the average day after the completion of the project.


After the Project (2021-2023)

The result of the project was that the traversal time was reduced by 9 seconds to 2 minutes and 38 seconds And perhaps most importantly, the average hours of delay reduced significantly (-21.77 hours per day).


Why? Are drivers now driving a more consistent speed across the corridor instead of racing from traffic signal to traffic signal? Could this result be explained by other improvements made during the project, such as changes to signal timing? Did the new project also change the speed limit for this corridor?

QUANTIFYING THE IMPROVEMENTS


Hours of delay is an effective Key Performance Indicator, capable of quantifying the difference in travel behavior before and after the project implementation. Hours of delay measures the extra amount of time spent in congested conditions defined by speed thresholds that are lower than a normal delay threshold. For the purposes of this measure, the speed threshold is 20 miles per hour or 60 percent of the posted speed limit, whichever is greater. This measure multiples the total hours of delay by traffic estimates for each segment to determine vehicle hours.


787 north experienced 60,000 hours of delay during the two year period before the project (2016-2018) and 36,250 hours of delay during the two year period after the project was completed (2021-2023) - a reduction of approximately 40%.


What does this mean for people? It means people spent less time in their car traversing this segment but they also spent less time traversing this segment at speeds well below the speed limit. Perhaps they spent less time waiting at stop lights? Perhaps the raised intersections moderated the racing from signal to signal?


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ANNUAL COST OF DELAY


Hours of delay can be quantified further as cost savings. We can apply a simple Delay Cost calculation of $15 per hour, per vehicle impacted to see the total impacts of the improvements:


BEFORE:

$451,000 /yr

AFTER:

$271,875 /yr

SAVINGS:

$179,250 /yr




What does this mean for people?


It means people spent less time in their car traversing this corridor but they also spent less time traversing it at speeds well below the speed limit. This means they could reliably traverse this corridor at a consistent speed instead of experiencing the frustration of starting and stopping.


Perhaps the raised intersections moderated speeds thereby reducing the tendency of drivers to race from one light to next? Perhaps they spent less time waiting at stop lights?


The bottom line is that drivers saved time and money due to the project.

Where do we go from here?


The results of this project leave some questions unanswered, the implications of which could be valuable for planning similar projects in the future.


  • Did the project result in less vehicular incidents or pedestrian injuries?
  • Did the project improve the pedestrian experience and increase the likelihood of walking trips?
  • Are there similar projects across the state that we can investigate to learn more about how the road modifications affect behavior?
    • Can we tease out the effect of raised intersections from signal re-timing?
    • Can we locate other signal re-timing projects in the state to better quantify the cost savings of signal timing projects in order to justify more of them?