UPS's no-left-turn rule, checked

What the rule really is, which of the famous numbers hold up, and the parts a small fleet can actually use.

First, whose rule is it?

You may have heard it called FedEx's "no right turn" rule. The famous rule belongs to UPS, and it is about left turns. In countries where people drive on the right, a left turn means crossing the lanes of oncoming traffic. UPS plans its routes so drivers make as few of those as they can. We found no record of FedEx having a turn rule like this.

Right-hand traffic. The left turn has to cross the oncoming lane; the right turn does not.

A preference, not a ban

"No left turns" is a catchy name, not the real policy. A UPS spokesman has called it a misnomer, and UPS has said its drivers still turn left about 10% of the time, more on rural routes. The goal is to avoid left turns that are not needed and to keep the truck on the side of the street where its door faces the stop. A 2017 CNN report said UPS's routing system can add about a 20-second penalty to an unwanted left turn. In other words, a left turn is allowed when it is worth it.

Illustration on invented streets. Three rights make a left: more distance, but no crossing traffic.

Where it came from

Popular accounts say UPS began telling drivers to avoid left turns in the 1970s, as part of planning delivery loops. Those accounts are consistent, but we could not find a UPS document from that time, so treat the date as reported. What is well documented is UPS's route planning system, ORION. It was first rolled out in 2012, covered about 55,000 US routes by 2016 and about 66,000 routes in North America and Europe by 2020. In 2020 UPS added changes during the day, so routes can update while the driver is out.

What UPS says it saves

These are the numbers people quote, and they are UPS's own. At full rollout UPS estimated ORION would save about 100 million miles, about 10 million gallons of fuel and about 100,000 tons of CO2 a year, worth $300 to $400 million a year. UPS said it had saved more than $320 million by the end of 2015, against a cost of about $250 million.

Two cautions. First, nobody has audited these figures in public. Second, they cover everything ORION does: stop order, loop planning and turn penalties together. There is no public breakdown of how much comes from left turns alone. Any article that says "no left turns saves 10 million gallons" is giving the rule credit for the whole system.

You may also remember a MythBusters episode that tested the idea. We could not verify its exact results, so we do not repeat them here.

The safety case is real

The safety reason holds up in federal data. In NHTSA's study of the events right before crashes, a car turning left was the key event in 22.2% of crashes. Turning right was the key event in just 1.2%. These are counts of crashes, not risk per turn, but the gap is very large.

Source: NHTSA, National Motor Vehicle Crash Causation Survey (crashes 2005 to 2007), DOT HS 811 366, Table A1.

An older federal study of 154 left-turn crashes found the turning driver usually caused them: in 49% the driver did not see the oncoming car, and in another 30% the driver saw it but misjudged its speed or the gap.

The cost: a little more distance

Avoiding left turns is not free. Going around the block adds distance. Researchers who studied banning left turns across a whole road network found it helps traffic flow but makes trips longer, and they suggest limiting left turns only at busy intersections. A 2023 study of real Florida roads found that capping the number of left turns on a 5 to 20 km trip made the path only slightly longer than the shortest one. The lesson is a trade-off: avoid the risky turns, and accept the easy ones.

How routing software handles turns

Modern routing engines can price each turn. GraphHopper, an open-source engine, supports turn costs and turn restrictions when it routes along road segments rather than points. That turns "no left turns" into a setting: give a left turn a time penalty, and the router avoids it unless the detour costs more.

What a food distributor can take from it

Use a penalty, not a ban. A few seconds per left turn steers routes without sending trucks on long detours.
Mind the curb. On city stops, arriving with the door toward the store saves walking a hand truck across traffic.
Let rural routes turn left. On empty country roads the detour usually costs more than the turn.
Watch the big ones. A left across a busy road with a long trailer is where the real risk is.
Do not expect UPS's numbers. A 20-truck operation will not save millions of gallons. The gain is safer days and fewer close calls.

Sources

Questions people ask

Does FedEx have a no-right-turn rule?

We found no record of one. The well-known rule belongs to UPS, and it is about avoiding left turns, which cross oncoming traffic in countries that drive on the right.

Do UPS drivers ever turn left?

Yes. UPS has said drivers turn left about 10% of the time, more on rural routes. The rule avoids unneeded left turns; it does not ban them.

How much does avoiding left turns save UPS?

UPS estimated its ORION routing system saves about 100 million miles and 10 million gallons a year. Those are UPS figures for the whole system, and there is no public number for left turns alone.

Are left turns really more dangerous?

Federal crash data says yes. In NHTSA's crash causation study, turning left was the key event before 22.2% of crashes, against 1.2% for turning right.

Should a small fleet ban left turns?

A penalty works better than a ban. Add a few seconds of cost to each left turn in your routing so trucks skip risky ones, but still turn left when the detour would cost more.