Performance evaluation parameters for signalized road intersections under heterogeneous traffic condition

Abstract

A study was carried out to evaluate the performance of the intersection in terms of delay based Level of Service (LOS), Accident Records and based on that appropriate countermeasures are recommended to improve the performance. In order to achieve the objectives of this study / research, at first a preliminary survey was organized around the Dhaka Metropolitan City area. In Dhaka Metropolitan City, there are ninety eight (98) major intersections, out of which sixty one (61) intersections were surveyed in this preliminary survey. From the preliminary survey, seven (7) important intersections were selected among the entire road network of Dhaka Metropolitan City on the basis of site selection criteria, focusing on their importance and geometric classification. After the finishing of preliminary survey of those selected intersections, the final field survey was performed. Detail data collection of various characteristics of intersections were done, such as geometric and operating condition, vehicular flow, pedestrian flow, side friction, traffic control devices, queue length, delay, accident record (reported), etc. Finishing this data collection, analysis of data was done. From this analysis, a delay based level of service (LOS) of different approaches of selected intersections was calculated as per standard stated in Highway Capacity Manual (HCM) and American Association of State Highway and Transport Officials (AASHTO). The overall LOS of those intersections was found out by following a statistical method named Average Method s was established based on LOS. From this ranking, the worst and best performing intersections were identified. This study incorporated with the reported accident data. Accident data was obtained from Accident Research Institute (ARI) of BUET for the period of sixteen (16) years (from 1998 to 2014). Finally evaluation of parameters for signalized / un signalized road intersections under heterogeneous traffic condition of Dhaka City, a delay based LOS and as well as ranking were established with respect to accident data.