In the recent years, traffic congestion in suburban areas has grown to a severe problem resulting in reduced economic productivity, deterioration of air quality and driver frustration. While the results from congestion in various systems are similar, the actual causes of congestion vary considerably from one system to another. Therefore, localized studies are necessary to determine the roots of the congestion problem at specific locations and propose appropriate solutions for its cure. This paper summarizes results from a congestion analysis study of Southfield Freeway, in Michigan. Southfield is located in the Metropolitan Detroit region, an area that has undergone dramatic demographic changes in the recent years. Significant population and employment growth in the neighborhood of the facility as well as commercial and retail development along the freeway contributed to a failure of the facility to serve the existing demand during peak hours. The study was organized as follows: (a) survey of field conditions; (b) survey of users perceptions about congestion; (c) analysis of historical traffic and incident data; and (d) identification of problems and proper solutions. Observation of current traffic conditions through a series of field trips provided insight into traffic flow conditions during peak hours, and information on physical properties of Southfield Freeway. Analysis of a questionnaire survey completed by Southfield commuters revealed valuable information on their travel patterns, and the perceived cause, location, and duration of congestion and assisted in the determination of specific locations that required immediate attention. Finally, historical traffic and incident records were analyzed and high risk locations along the study section were identified. Based on the results from the analysis discussed above, specific congestion-relief measures were proposed. This paper describes the steps of the data collection and reduction effort, presents results from the data analysis and conclusions, and lists proposed congestion-relief actions. Implementation of such actions is expected to improve the level of service of the facility, reduce delays and travel time, facilitate smoother flow of vehicles during the peak periods, and improve the level of satisfaction of the average user. (A)
Samenvatting