Post by Maria Kolar, Marketing Manager at Waycare

Last month, while enjoying a nighttime drive home from the gym, I experienced firsthand the dangers of left turns. Taking a brief detour to stop into my local drugstore, I prepared to turn left at the intersection. As I began to make the turn, I quickly realized my mistake – seeing the headlight of a motorcycle speeding through. I slammed on the brakes, only to learn that I was not quick enough as I heard the dreaded crunch of metal-on-metal.

Both the motorcyclist and I walked away with minimal damage, but the same could not be said for our vehicles. In addition, the insurance company verified that despite the motorcycle speeding through, the vehicle turning left will almost always be at fault. I learned a lot from this experience, particularly the dangerous nature of left-hand turns and the liability one has when making this maneuver.

Federal research shows that about forty percent of car crashes occur in intersections, most of them due to left-hand turns. One company has been aware of this for over a decade. UPS is one of the world’s largest courier, freight, and logistics companies. Over a century old, it employs nearly half a million people and operates 119,000 vehicles. The company knows a thing or two about navigating roads and traffic; their bottom line depends on it. So in 2010 when Senior VP Bob Stoffel revealed to Fortune magazine that UPS saves time by avoiding left-hand turns, it got a lot of attention.

“We’ll never have a person turn left to deliver on that side,” Stoffel explained. “We’ll have someone go down the right-hand side and someone coming back down the right-hand side, to avoid those left-hand turns.” In other words, UPS plots its delivery routes in a right-turning loop.

As a result, the company has likely avoided thousands of crashes and saved millions of dollars in fuel in the process.

Why are left turns problematic?

Many left-hand crashes occur because of an obstructed view, a misjudgment of speed, or a false assumption of another driver’s planned action.

“Left turns are tricky because drivers must make a complex series of judgments in a short period of time. Is the light about to turn? Are all the oncoming lanes clear? And why is the guy behind me honking?” said Anne McCartt, Senior VP for Research at the Insurance Institute for Highway Safety.

Jeff Shaw, of the Federal Highway Administration, added to McCartt’s argument,

“The more and more a driver has to process, the more likely it is a mistake could be made.” Split-second judgments more frequently lead to traffic crashes.

What can be done to reduce the dangers of left-hand turns?

City planners and traffic engineers are aware of the need to design safer, more maneuverable intersections. For example, some cities have installed road features like “slow turn wedges” and “centerlines” to encourage drivers to follow an organized path when passing through.

Other cities are turning to technology to alleviate the problems around intersections. In Detroit, a system of sensors and connected traffic signals was deployed to trigger responses to real-time factors such as cyclists and emergency vehicles. The system can automatically make changes to signal timing, prioritize certain modes of transportation over others, and encourage freight use to move away from pedestrian-heavy corridors.

Other cities should take note from Detroit’s use of smart intersection technology. Taking advantage of the immense amount of information coming from connected vehicle sensors can help traffic management teams make vital changes to intersections. In fact, Iowa State University reports that using vehicle-to-infrastructure (V2I) information to prioritize signal timing could prevent an estimated 575,000 crashes and 5,100 fatalities per year.

A common stance in the transportation industry is that autonomous vehicles (AVs) will remove human error thus eliminating crashes both in intersections and beyond. While I agree that the inevitable prevalence of AVs will likely increase safety, it is still many years away from existence. In the meantime, cities must prepare for this transition by embracing the smart mobility solutions of today.