Figure 33: Street chosen for closure (7th Street from Fort Duquesne to Penn Ave

Figure 33: Street chosen for closure (7th Street from Fort Duquesne to Penn Ave)

Based on the VISSIM model, there is a total of 66 OD routes that are going through the 7th Street from Fort Duquesne and Penn Ave. Therefore, to apply findings from modeling the work-zone during the PM peak conditions to the other hours during the day, a methodology was developed that utilizes field travel times (reported by Google) to understand differences in delays and travel times between the PM peak hour and other hours. Then, based on such differences, the delay adjustment factors were calculated that would be applied to PM peak hour delays to estimate delays for all other hours during the day. To ensure that the analysis of the various routes is done with enough detail and in given timeframe, the analysis was reduced to a total of 23 routes with the most significant volumes.

After reviewing the selected routes, applicable detours were developed for each route and the extent of vehicles which was rerouted was based on the respective significance of the travel time which would be experienced by that route (avoiding the closed link on the 7th street). The workaround was the best approach without considering a large-scale traffic assignment scenario which is outside the scope of this project. Consequently, the vehicles in the VISSIM simulation were prevented from entering the link that represents 7th street. All 66 routes originally passing through the 7th Street were rerouted to the other local streets. Rerouting was done based on the minimum relative travel times for the relevant substitutes of the closed route. In the cases where Google travel times were too similar for two alternative routes, one with the shortest distance was taken into consideration.

The Google travel times were collected for the entire 24-hour period. However, to avoid working with too many periods, which are unnecessary, periods were stratified into five distinctive time windows with similar traffic conditions, according to PennDOT data shown in