Traffic Safety and Built Environment

Bangladesh is one of the most hazardous countries in the world in terms of road crashes. According to police reports, around 2,800 or more road crashes occur in this country every year. Moreover, pedestrian crashes have become a major safety concern in urban areas. From 1998 to 2013, more than 10,000 crashes occurred in Dhaka, the capital and megacity of Bangladesh, and 4,514 pedestrians died in those crashes. To improve this critical situation, researchers have been trying to identify the contributory factors behind crashes through studies at both microscopic and macroscopic levels. It is possible to improve road safety by altering the built environment of urban areas, considering its relationship to crash occurrences, since the built environment has a strong direct influence on traffic volume, speed, and conflicts. Therefore, understanding the contributory built environment factors behind crashes is very important for taking effective countermeasures to reduce crashes, and consequently, improve road safety, including the safety of pedestrians. This study:

• Explored the effects of human, vehicle, roadway, built environment, and natural environment-related factors on pedestrian and motorcycle crash severity in Dhaka using binary logistic regression.

• Developed a spatial regression modeling framework that integrates global non-spatial regression (linear regression, logistic regression), global spatial regression (spatial lag model, spatial error model), and local spatial regression (GWR, MGWR, GWLR) models to address spatial autocorrelation and explore the spatially heterogeneous effects of the built environment on pedestrian crash occurrences and severity.