Why Banning Left Turns at Intersections Could Save Lives and Reduce Traffic Jams
Did you know that more than 60% of traffic collisions at intersections involve left turns? This alarming statistic has prompted some US cities, such as San Francisco, Salt Lake City, and Birmingham, Alabama, to consider restricting left turns at certain intersections.
Dr. Vikash Gayah, a professor of civil engineering at Penn State University and the interim director of the Larson Transportation Institute, explains why left turns can be so dangerous. When making a left turn, drivers have to cross oncoming traffic, increasing the risk of angle crashes, one of the most dangerous types of collisions. Additionally, left turns can also pose a threat to pedestrians crossing the street.
Statistics show that approximately 40% of all crashes occur at intersections, with 61% of these involving left turns. This highlights the unique dangers associated with making left turns at intersections.
Left turns are not only hazardous but also inefficient for traffic flow. When vehicles wait to make left turns, they can block other lanes, causing traffic congestion. Implementing restrictions on left turns during peak periods can help alleviate traffic congestion and make intersections more efficient.
One alternative to left turns is the use of roundabouts, which eliminate the need to cross opposing traffic. While roundabouts are safe, they may not be as efficient in busy urban areas due to potential gridlock issues.
Despite the initial discomfort of banning left turns, the benefits are clear. Eliminating left turns can lead to longer travel distances but results in quicker travel times and reduced fuel consumption. In fact, vehicles that avoid left turns can save up to 10-15% on fuel per trip.
While banning left turns may be a new and unfamiliar concept for some, the potential benefits in terms of safety, traffic efficiency, and fuel savings are compelling. As more cities explore this strategy, we may see a shift towards safer and more efficient urban transportation systems.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
Vikash V. Gayah, Associate Professor of Civil Engineering, Penn State
