More cities ban left turns. The reason is not just safety

An increasing number of cities globally are implementing bans or restrictions on left turns, a maneuver that traffic safety specialists consider one of the riskiest driving actions. This strategy aims to mitigate traffic congestion and enhance road safety.

Professor Vikash V. Gayah, a transportation engineering specialist at Penn State University, explained in an analysis published by The Conversation that left turns require drivers to cross oncoming traffic. Misjudging the timing can lead to collisions with vehicles coming from the opposite direction, a particularly dangerous type of accident. In countries where traffic drives on the right, left turns can slow down circulation as drivers navigate opposing lanes, pedestrians, and cyclists, creating multiple conflict points.

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When you make a left turn, you have to cross the traffic from the opposite direction. If you misjudge the moment, you can hit or be hit by a vehicle coming from the front. This is one of the most dangerous types of accidents.

To address these issues, experts propose alternatives such as driving straight and then making a right turn, or establishing dedicated U-turn points. While these routes might be slightly longer, they can ultimately save time by preventing traffic blockages. Professor Gayah notes that intersections without left turns can process more vehicles, reducing waiting times and leading to quicker arrival at destinations.

This approach has proven effective for companies like the American courier service UPC. For over a decade, UPC's software has planned routes to minimize left turns, resulting in significant annual savings of fuel, reduced CO2 emissions, and a notable decrease in accidents. This model has even been studied by traffic planning authorities.

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Even if drivers sometimes travel a slightly longer distance, each intersection without left turns can handle more vehicles. This means the waiting time decreases, and in the end, you reach your destination faster.