UPS has banned its drivers from turning left since 2004. The company says the rule saves 10 million gallons of fuel a year and let it pull 1,100 trucks off the road. The same logic is why this intersection needs zero lights.
The left turn is the villain of the entire road system.
A normal four-way intersection has 32 points where two cars can hit each other. Sixteen of them sit inside the box, and every one of those is a crossing conflict, the kind that produces a T-bone at 45 mph. Twelve of the sixteen involve someone turning left across oncoming traffic.
Delete the left turn and the count drops from 32 to 14. Crossing conflicts fall 87%.
That is what the loops in this design are doing. Nobody turns left. You turn right, drive a few hundred feet, U-turn through the median, and come back to the road you wanted. Three gentle merges replace one gamble against oncoming cars.
Michigan has been building these since the late 1960s, which is why engineers call it the Michigan Left. Minnesota put its first one in Willmar and went three years without a single fatal or serious injury crash. Across the states that adopted the design, injury and fatal crashes fell 54%.
The render skips the cost. Every crossing driver goes farther, and those U-turn loops eat land, which is why you find these on wide rural highways and almost never downtown. Minnesota’s math is that it can build 10 to 20 of them for the price of one overpass.
Traffic lights exist to referee left turns. Take the left turn away and the referee has nothing to do.
UPS has banned its drivers from turning left since 2004. The company says the rule saves 10 million gallons of fuel a year and let it pull 1,100 trucks off the road. The same logic is why this intersection needs zero lights.
The left turn is the villain of the entire road… https://t.co/JBIUfQf67R
— Aakash Gupta (@aakashgupta) September 4, 2026