Abstract
This study examined the potential crash reduction benefits of public safety campaigns aimed to positively impact the traffic safety culture for young drivers. Crash modification factors (CMFs) for State of Idaho’s SHIFT public safety initiative were developed using Idaho specific crash data covering the period from 2014 to 2020. The CMFs developed as part of this project allow the Idaho Transportation Department (ITD) and other local, state, and federal transportation agencies to assess the potential safety benefits of public safety campaigns. Generalized linear negative binomial models were used to develop crash prediction models which were used as safety performance functions to predict the number of crashes had the tested safety measure (public safety campaigns) not been implemented. The previous literature studies show that the negative binomial model appropriately accounts for both the randomness as well as the overdispersion in the crash count data. The models established were only for the total crashes and fatal and severe injury crashes. Specific crash types were not addressed due to insufficient sample size. The results of the Empirical Bayes method used in this study can be summarized as follows:
· Public safety campaigns can reduce the crash rates, and particularly amongst the youths of age group 15-19. The analysis showed that there was significant reduction in fatal crashes as well as total crashes for the age group 15-19 by 24.81% and 5.80% respectively.
· Similarly, the age group 20-24 and 25-44 had significant reduction in fatal crashes by 20.75% and 16.29% respectively.