Modeling and Evaluating the Impact of City Block Size on Traffic Performance

Abstract

This paper investigates how block size influences traffic by dividing the travel distance, time, and number of turning maneuvers into two parts: the one that happens inside the block, and the one outside. We develop analytical formulations that yield representative values of the three aforementioned indicators under low-demand scenarios. A VISSIM simulation with a dynamic traffic assignment is used to verify such values, study the traffic behavior for high-demand scenarios, and evaluate the traffic performance, network capacity, and resiliency. The results indicate that traffic inside the block plays a more important role on the overall performance in networks with larger block size and/or short trips. In addition, smaller block-size networks yield shorter travel distance and better travel accessibility, as well as higher network capacity; whereas larger block-size networks have shorter travel time and smaller number of turnings under low-demand levels. In the congested situation, the larger block-size networks show relatively better performance as they take longer to become congested and gridlocked.