A method for simplifying the analysis of traffic accidents injury severity on two-lane highways using Bayesian networks

IntroductionThis study describes a method for reducing the number of variables frequently considered in modeling the severity of traffic accidents. The method's efficiency is assessed by constructing Bayesian networks (BN).MethodIt is based on a two stage selection process. Several variable selection algorithms, commonly used in data mining, are applied in order to select subsets of variables. BNs are built using the selected subsets and their performance is compared with the original BN (with all the variables) using five indicators. The BNs that improve the indicators’ values are further analyzed for identifying the most significant variables (accident type, age, atmospheric factors, gender, lighting, number of injured, and occupant involved). A new BN is built using these variables, where the results of the indicators indicate, in most of the cases, a statistically significant improvement with respect to the original BN.ConclusionsIt is possible to reduce the number of variables used to model traffic accidents injury severity through BNs without reducing the performance of the model.Impact on IndustryThe study provides the safety analysts a methodology that could be used to minimize the number of variables used in order to determine efficiently the injury severity of traffic accidents without reducing the performance of the model.

► It is possible to reduce the number of variables in the analysis of traffic accidents.
► A selected subset of variables can improve the performance of traffic accidents models.
► Seven variables were found to be the most significant in traffic accidents injury severity.