Street Connectivity versus Street Widening: Impact of Enhanced Street Connectivity on Traffic Operations in Transit-Supportive Environments

• Published in: Transportation research record 2015-01, Vol.2494 (1), p.57-68
• Main Authors: Tasic, Ivana, Zlatkovic, Milan, Martin, Peter T., Porter, Richard J.
• Format: Article
• Language: English
• ISSN: 0361-1981; 2169-4052
• DOI: 10.3141/2494-07

Highly connected street networks increase accessibility for multimodal transport, but their effects on the efficiency of still-dominant vehicular traffic is rarely addressed. As interest increases in transforming typical suburban developments from car-oriented to multimodal environments, the effects of redesigned street networks in the period before the expected mode shift need to be clarified. This paper addresses the effects of enhanced connectivity on traffic operations and uses part of the West Valley City, Utah, network as the potential transit-oriented development (TOD). Because the predicted traffic demand for 2040 requires modifications to this network, the question is whether enhanced connectivity as a TOD-supportive approach can accommodate that demand and replace the traditional street widening solution. Twelve scenarios were modeled and evaluated: the existing state, five scenarios with different levels of street connectivity, five street-widening scenarios, and a scenario with reduced speed areas based on traffic-calming practices. Macro- and microsimulation models were used iteratively to build, calibrate, and evaluate the modeled scenarios. The results at the intersection, corridor, and network levels showed that enhanced street connectivity represented a competitive alternative to the traditional capacity expansion approaches that usually involve street widening. As connectivity increased, the network designs with enhanced connectivity accommodated more traffic than the designs with street widening and therefore opened new routes and provided a better dispersion of intrazonal traffic. New scenarios that encompass changes in mode split are proposed for future research efforts.