Accident black spots identification for safety improvement on a section of Dhaka-Chittagong highway

Abstract

This thesis presents the findings of the study concerned with accident blackspot identification for improvement of safety on the Jatrabari-Kanchpur Bridge section of Dhaka-Chitlagong highway. The selected section of Dhaka-Chitlagong highway is composed of three intersections and nine links. The study examines the trends and characteristics of the accident problem for identifying the dominant accident types which need to be addressed in future initiatives. A total of 356 Accidents oecurred on this highway section in a time period of 4 years from January 1998 to December 200 I. Out of total 356 reported accidents, 34% occurred at or near intersections and remaining 66% occurred on links of selected section of highway. The accidents occurring in the study area are classified as 49% fatal, 39% injury, 12% property damaged. The involvement of pedestrian in the accidents occurring in the study area is significant comprising 54.21 percent amongst the various classes of road users. Rear end accident is also identified as a dominant problem. In the study area, occurrence of accident is higher during day time than night time and the frequency of the occurrence of accident is the highest between 8 AM to 12 at Noon. Buses are involved in 40 percent of total accidents, followed by tmcks and mini buses with 30 and 9 percent, respectively. Detailed investigation of black spots are made using available accident data, field investigations and video data. For the purpose of the analysis, inforrnation availablc Ii'om FIR. Accident Report Forms and Register books is coded into a number of variables to correlate occurrence of accident with traffic system variables. Eight relevant. variables are extracted and used in subsequent analysis. As "- blackspots are related with roadway environment related variables, on the basis of the variables mentioned above the involvement of road environment is analyzed by using 'Principal Component Analysis (peA)' method. The aggregate factor weight of roadway environment in the total number of accidents occurring at a location is graphed onto the roadway section. The locations where the aggregate weight of roadway environment factor is more than the average is identified as black spot. From the analysis, five locations are identified as accident black spots. The locations arc Jatrabari intersection, Dania College. ICMII at Matuil, Saddam market and Kanchpur Bridge (western part). The highest number of accident occurred at Jatrabari intersection which is followed by Kanehpur Bridge, ICMII at Maluil, Dania College and Saddam marke!. In order to reduce the risk of accidents at the hlack spots, the study recommends construction of underpasses at the level of approaching road, grade separation for non-motorized traffic, construction of footpath for pedestrian movement, grade separated bus stops and channelization of traffic at intersections in the study area.