Left turns are among the most dangerous maneuvers a driver can make, particularly when sharing the road with pedestrians, bicyclists and motorcyclists. They’re also surprising fuel-wasters as cars idle waiting for a light to turn or a break in traffic – so much so, that delivery giant UPS routes its drivers to avoid them as much as possible.
In a now-classic study, the National Highway Traffic Safety Administration found that 36% of collisions occur at intersections. In what it dubbed “critical reasons” for the crashes, recognition errors (inattention) accounted for 41%, decision errors (speeding, driving too aggressively) accounted for 34% and performance errors (overcompensation) accounted for 10%. Distractions and fatigue also contributed.
Separate research reported in the Washington Post notes that among all intersection crashes, more than half are left turns compared with slightly fewer than 6% for right turns. More than one-third of fatal motorcycle crashes involve a vehicle unexpectedly turning left in front of them.
What makes left turns so tricky?Left turns require a challenging combination of visual, spatial and physical coordination and can be complicated further by age-related vision changes. A recently released report by the Insurance Institute for Highway Safety notes that driver-assist technology now in development may reduce intersection crashes among mature drivers by more than 30%.
Those technologies use a combination of cameras and other sensors to detect oncoming vehicles when a driver turns on their blinker. It warns them if it senses a collision is likely and, depending on the system, may automatically brake to prevent it.
Current crash-avoidance technology like front-crash prevention, lane departure warnings and brighter, better-aimed headlights also can help reduce intersection crashes.
Why don’t UPS drivers turn left very often?UPS drivers turn left only about 10% of the time, relying instead on the company’s sophisticated proprietary routing system to loop them through the streets using a series of right turns. The company began favoring right turns as far back as the 1970s, but GPS technology took its preference for right turns to a new level in the early 2000s.
Even though occasionally looping the block makes some routes longer, the company estimates it cuts annual fuel consumption by 10 million gallons, emits 20,000 fewer tons of carbon dioxide and still manages to deliver 350,000 more packages a year. Overall, the carefully orchestrated routes reduce distances traveled by 28.5 million miles.
Check out this video that will get you turning right more often, too! And for more on intersections and traffic safety, see our Blog for Road Rules stories like these: Turning onto a multilane road and Center turn lanes.
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