Road diets had little effect on emergency response vehicles although motorists could be better educated on how to properly yield to the vehicles. At least that was the case in one Midwest city.

“Impact of 4-to-3 lane conversions on emergency response,” a study published in Transportation Research Interdisciplinary Perspectives, examined the impact of such road diets on emergency response in Cedar Rapids, Iowa.  Researchers at the University of Iowa College of Public Health’s Injury Prevention Center analyzed 170 survey responses and EMS data.

The Hawkeye State was among the first states to implement such conversions in the 1990s. The 4-to-3 lane conversions attempt to smooth traffic flow and reduce crashes with the addition of a dedicated center turn lane while providing more space for bike lanes or parking.

More than half of EMS respondents believed there was no effect or a positive effect on responses while 40 percent believed there was a negative effect, which they attributed to driver confusion on how to properly yield to emergency vehicles.

While there was a lack of evidence of an effect on EMS response rates overall, results indicated that public guidance on how to properly respond to the presence of emergency vehicles may be needed. “Results of this analysis may be applicable to other lane conversion sites when appropriately combined with local context relevant to the target area,” according to the study.

Read the full 12-page study here.