[CATEGORY Total User Cost of Delay for Arterial Network [CATEGORY NAME], 2,674.7, [PERCENTAGE ]
NAME], 4,688.4, [PERCENTAGE ]
[CATEGORY NAME], 116,281.9, [PERCENTAGE ]
Figure 35: Total User Cost of Delay for Downtown Pittsburgh In the arterial analysis, a few scenarios with different volumes show that a work-zone street closure in Pittsburgh Downtown area can cause user delay costs in the range of $102,779 to $123,645. The difference in models' delays, with and without work-zone, shows that such a street-closure work zone can increase the network's total delay by around 11%. It is essential to mention that the user delay costs incurred during 1.5 days of closure would be much lower if the extra half of the day is time overnight when traffic volumes are their lowest point. This demonstrates the importance of short construction time in urban areas. A significant amount of user delay cost can be saved by cutting down the length of time a roadway must be closed for construction. Even a few hours saved can lead to tens of thousands of user cost saved for the project. Early opening is especially crucial to urban areas because of the effect on neighboring streets. The passenger cars that typically take the roadway under construction are forced onto other routes creating significant delays, as shown in the 11% network delay from the example. Departments of Transportations and drivers can see the benefits of reducing the road closure time to significantly reduce user costs and congestion. This allows concrete construction in an urban environment while limiting the closure time but retaining the long-term performance concrete pavements are known for. However, this study presents several limitations. First, traffic volumes were available only for PM peak hours. Thus, estimation of volumes for other hours was done based on adjustment factors. Second, traffic in the VISSIM model routed through a set of static routes, and the rerouting (due to the work-zone street closure) needed to be done manually. Such an approach reduced the stochastic nature of the traffic and could have a minor-to-moderate impact on the model’s outputs. In the future, the model should use dynamic traffic assignment (DTA). Finally, various elements of modeled network should be calibrated and validated. 70
