IMPROVING CIRCUITY AND TRAFFIC SAFETY IN URBAN ROADWAY NETWORK: Using the Multiple Loop Systems - Conceptual Formulation

摘要

Costs of inefficiencies built into the existing system of road transportation in cities in the United States are staggering: $275 billion for road accidents, 17.3 billion gallons of wasted energy utilization, and an equally staggering amount of carbon monoxide as well as carbon dioxide released into the atmosphere, all in one year, on top of accident costs and personal strain. As our natural resources are limited, it is essential that existing transportation systems be re-evaluated such that transportation systems positively contribute to the realization of sustainable and livable communities in the urbanized areas. In an effort to design road networks which would improve circuity and traffic safety, Raswant developed a series of circuity systems, called the Multiple Loop System, based on an urban planning concept that integrates land-use and street network. At its macro level, MLS is perceived as a road network consisting of multiple of one-way endless (closed) loop roads surrounded by other similar roads. Adjacent loop roads are required to circulate traffic in opposite directions relative to one another, and are interconnected by one-way or two-way streets. MLS is versatile and can be fit to a variety of urban road networks. A micro-cluster analysis modeled after MLS was applied to Manhattan's street plan to experiment the concept to an existing grid network and to evaluate its potential impact on traffic evaluation parameters such as delay and travel time. It was found MLS may increase travel distance but can decrease travel time by minimizing delays and improve traffic safety.