VULNERABILITY ASSESSMENT OF MOTORCYCLE RIDING IN DHAKA CITY BY STRUCTURAL EQUATION MODELLING

Abstract

In recent years, motorcycles have become one of the preferred modes of transport for commuters of Dhaka city as an alternative to car travel and public transports for its affordability and easy accessibility to reach any destination. This massive raise of the number of motorcycles has increased accidents and consequent casualties which is a growing problem for the urban dwellers of Dhaka metropolitan city. It is quite evident that motorcyclists are being forced to share the road with mixed traffic due to absence of separate motorcycle lane in road infrastructure. Thus, it has an associated safety concerns as well as psycho-social impacts on motorcyclists and other road users in Dhaka city. In view of the mixed traffic situation, the study has been intended to assess the overall vulnerability of motorcycle riding within the existing roadway characteristics and traffic management system of Dhaka city from the two-folded safety perceptions and reported behaviours of motorcyclists as well as other road users by Structural Equation Modelling (SEM). The research methodology has been designed into three-steps procedures to develop and analyze the models. In the first step, a set of 26 and another set of 24 perceived safety concerns variables have been selected for Motorcyclists as well as Other Road Users respectively. Secondly, two sets of stated preference survey questionnaire have been administered among motorcyclists including service riders as well as other road users including pedestrians, car and public transport drivers in the Dhaka city by both field and online questionnaire survey. Then, two Structural Equation Models on the safety concerns of motorcycle riding have been generated by carrying out by 1 st and 2nd Order Confirmatory Factor Analysis (CFA) method using the Stata software. Finally, both the models have been analyzed basing on the ranking values of standardized factor loading of all the latent and observed variables to determine the Most Significant/Important and Significant/Important factors related to the overall vulnerability/ safety concerns of motorcycle riding in Dhaka city. The study has unveiled that comparing both models, all the perceived safety concerns of motorcycle riding in Dhaka city are being recognized by both Motorcyclists as well as Other Road Users. Only there are differences of perception from both ends in prioritizing or ranking the safety factors in different safety aspects. As such, in the mixed traffic iii situation of Dhaka city, the five safety aspects like Road Infrastructures (n1), Traffic Management System (n2), Traffic Rules Violation by Motorcyclists (n3), Psycho-social aspects influencing riding of Motorcyclists (n4) and Traffic Rules Violation by Other Road Users (n5) are the determinant safety concerns and mutually influencing for the overall vulnerability assessment of Motorcycle Riding in Dhaka City. Amongst the 05 safety aspects, Traffic Rules Violation by Motorcyclists (0.87) is identified by both Motorcyclists and Other Road Users as the most significant safety concerns for vulnerable motorcycle riding in Dhaka city. In regards to Traffic Rules Violation by Motorcyclists, the result shows that frequent changing the lane by zig-zag driving (0.89), disregarding the speed limit by motorcycle drivers (0.89), uncertain movement of roadside parked motorcycles (0.89), using footpath by motorcyclists while stuck in traffic on main road (0.86) and overtaking any vehicle without proper precautions (0.82) are the most significant priority concerns as exhibited by the reported behaviours of motorcyclists. It is revealed in the analysis that motorcyclists’ attitudes and aggressive behavioural issues are influenced by various family and psycho-social issues which lead to commit an accident. The most significant psycho-social factors are riding aggressively during social or family crisis (0.96), breaking traffic rules to reach the destination at the earliest (0.89), violating the traffic rules during office time (0.89), ‘maximum income within shortest possible time’ by the service riders (0.87), driving fatigue for overstressed riding time by service riders (0.87). The certain traffic rules violation by other road users (public transport drivers, private cars drivers and pedestrians) also has a significant contributing impact on vulnerability of motorcycle riding in Dhaka city. The reported behaviour of other road users like not wearing helmet or other safety gears properly by the passengers (0.89) is identified as most significant safety concerns by both Motorcyclists and other road users. The study shows that road geometry and infrastructures of Dhaka city are not user-friendly and great safety concerns of motorcycle riding. The most significant safety concerns are absence of separate lane for motorcycle in mixed traffic flow (0.88 which is rated as top priority concern by both Motorcyclists and Other Road Users) and no footpath for walking or occupied footpath for other purpose (0.81). The study also reveals that absence of road signage / non-functional signal at a junction (0.78) and presence of unmarked elevated speed breaker (0.67) are the significant safety concerns in respect of traffic management system of Dhaka city. The outcome of this research can be a good instrumental tool for formulation of safety programs and policies for a safe motorcycle riding in Dhaka city.