Assessing the effectiveness of autism spectrum disorder roadway warning signs: A case study in New Jersey

Abstract

In 2018, the Centers for Disease Control and Prevention (CDC) found that the prevalence rate for children identified with autism spectrum disorder (ASD) in New Jersey is 1 in 35 children, the second highest rate of ASD diagnosis in the country. Children with autism face numerous obstacles, including learning road safety and interacting with road elements that could raise the risk of their traffic crash involvement. Many agencies across the nation have used disability warning signs as a tool to eliminate such risks. However, the effectiveness of these signs has not been explored yet. This study assesses the effectiveness of specific disability warning signs for autism at multiple locations in New Jersey using video and speed data. To investigate all drivers' responses to the ASD warning signs, the study defined two proxies of following the speed limit and applying brakes to show caution, where the events that did not correspond with the defined proxies were recorded as non-compliance events. Additionally, the Mann-Whitney U test was employed to evaluate the effectiveness during the presence and absence of ASD sign. Study results showed a high rate of non-compliance events for both proxies, and no significant difference in the driving speed was observed during the presence and absence of ASD sign. Additionally, the estimated relative risk/rate ratio revealed that the drivers that did not follow the speed limit were 1.5 times more likely not to apply brakes than the drivers who followed the speed limit, representing careless driving behavior in the area with ASD individuals.