Black Spot Identification, Analysis and Improvement Measures on Selected National Highway Stretches in Kerala, India

ABSTRACT The location in a road where the traffic accidents often occur is called a Black Spot. In these black spots accidents are not a ‘random event’ but accidents are common due to varying factors. In this study the accident statistics on three National Highway stretches spanning over 165 kilometers in Kerala, India is taken for the analysis and suggestion for improvement measures. The data is collected from the police records from September 2006 to August 2009 and analyzed using accident frequency and severity index methods to identify the accident black spots in the selected stretches. The identified black spots were ranked in terms of their frequency or severity and, the top ranked spots are taken for more detailed analysis by taking into account of the roadway and traffic conditions. The necessary site details were obtained by conducting the surveys. Geometric surveys are done for the stretches using total station surveys, the plan and profiles are made with the help of software packages MICROSTATION and GEOPAK. Autoturn 6.1 software and AUTOCAD 2008 is also used for turn simulations. The collected data is analyzed to suggest the appropriate improvement measures for each location. In this study eight accident black spots over six stretches which include two intersections, four black spots at curves and two mid block sections were taken for the analysis and suggestion for improvements. The range of improvements suggested include from simple traffic enforcement to widening and realigning of stretches by considering the cost involved in implementing the improvement measures.