An ordered-probit analysis of enforcement of road speed limits

The effectiveness of speed limit enforcement (SLE) is a critical factor in reducing the global burden of fatalities and injuries due to road crashes. A random-parameter ordered-probit model was developed to explore the relationship between the effectiveness of SLE and different explanatory variables using data from a 2013 World Health Organization global road safety report. An attempt was made to understand the complex interactions between SLE, socio-economic factors, other critical key risk factors and their enforcement levels. Socio-economic status, public policies and road safety legislation and its enforcement were found to be significantly associated with different level(s) of SLE (very low, low, medium and high enforcement levels). Out of seven significant variables, two variables – effectiveness of seatbelt enforcement and road safety audits of new roads – were found to be normally distributed random parameters, suggesting that their effects vary in different countries. The model findings provide preliminary insights into how socio-economic characteristics, road safety policies and traffic laws can be associated with SLE.