Impact of 4-to-3 lane conversions on emergency response

Abstract

4-to-3 lane conversions, often called road diets, have been implemented throughout the U.S. as a means to reduce crashes. However, the reduction in lanes has led to community wide concerns across the country regarding the possible negative effect on emergency responses. This study investigates the impact of 4-to-3-lane roadway conversions on emergency response in Iowa through surveys and a retrospective analysis of EMS data. The 170 survey responses were analyzed descriptively, and a text analysis was done on two open text survey questions. Generalized linear models were constructed to examine the impact of lane conversions on emergency response times. Over half of EMS respondents believed there was no effect or a positive effect on responses, while 40% believed there was a negative effect. The negative effect was often attributed to driver confusion on how to properly yield to EMS vehicles. Despite the differing perceptions, EMS response rates from before to after the implementation of 4-to-3 lane conversions did not meaningfully differ. Overall, there was a lack of evidence of an effect of 4-to-3 lane conversions on EMS response rates in Cedar Rapids, Iowa. However, survey results showed that public guidance on how to properly respond to the presence of EMS vehicles on these roadways may be needed. This study provides evidence for addressing local concerns about road diets and emergency response to add to other known safety benefits. Results of this analysis may be applicable to other lane conversion sites when appropriately combined with local context relevant to the target area.