2023 - USA - Effect of Lane Width on Traffic Safety

Report dispelling the myth that wider lanes improve road safety.

Overall, this study found no evidence that narrower lanes are associated with the higher number of crashes and that narrow lanes (9-foot and 10-foot) increase the risk of vehicle accidents, after controlling for cross-sectional street design characteristics and other confounding variables. Quite contrary, our models confirm that in some cases (in the speed class of 30–35 mph), narrowing travel lanes is associated with significantly lower numbers of non-intersection traffic crashes and could actually contribute to improvement in safety. These findings are novel with groundbreaking and immediate policy/practical implications for identifying streets in each road class as the best candidates for lane width reduction projects.