Truck Blind Spots (No-Zones): Driving Safely Around Semis

Big-rig blind spots, which the Federal Motor Carrier Safety Administration (FMCSA) calls No-Zones, sit about 20 feet in front of the cab, 30 feet behind the trailer, one lane to the left and two lanes to the right. A driver in any of those areas is often invisible to the truck driver, so the safest move is to pass steadily or stay out of them.

The size gap explains the danger. FMCSA materials compare a loaded truck at up to 40 tons with a car at about 2 tons, and say a truck needs about 40 percent more distance to stop. In 2024, 5,340 people died in crashes involving large trucks, and 70 percent of them were occupants of other vehicles, according to NHTSA data released in 2026.

Because trucks are so much heavier, crashes with them tend to be serious, and questions about how truck crash claims differ from ordinary car accident claims come up often afterward. Staying out of the blind spots is the better path, and it is a skill any driver can learn.

Where are the blind spots around a semi truck?

A tractor-trailer has four large blind areas, and the biggest is on the passenger side. The table below shows where each one sits and what to do about it.

A simple test works in any lane. The truck driver relies on the side mirrors and the mirror view behind the trailer, so a car that cannot be seen in those mirrors cannot be seen at all.

How do you pass a big rig safely?

Pass on the left, move through the blind spot at a steady speed, and do not move back in until the whole front of the truck is visible in the rearview mirror. Passing on the left matters because the left blind spot is smaller than the right, which shortens the time a car is hidden.

Passing is safest on a straight, level stretch with plenty of room ahead. Check the mirrors, signal, accelerate smoothly past the cab, and avoid passing just before an exit or on a curve where the truck driver cannot see oncoming traffic.

Cutting in too early is a common and dangerous mistake. FMCSA says trucks take 40 percent longer to stop, and a truck traveling at 65 mph can need up to two football fields to come to a halt. A car that slips into the gap and then brakes can leave the truck driver with no room to react.

Passing a truck on a downgrade, in rain or in snow takes extra care. Spray from the wheels reduces visibility for both drivers, and trucks in winter can shed sheets of snow and ice from the roof of the trailer. Leaving more space, or waiting for a clear stretch, is better than trying to squeeze past in poor conditions.

Why do big rigs need so much room to stop?

Weight and momentum make a loaded truck slow to react, even with a skilled driver and good brakes. A truck at 65 mph can need up to two football fields to stop, according to FMCSA, and wet or icy pavement stretches that distance further.

That is why sudden stops in front of a truck are so risky. A driver who brakes hard right after merging, or at an exit ramp, can leave a truck with no room to slow down. FMCSA also warns drivers not to get pulled under a trailer, which can happen when a car ends up too close behind a stopped or slowing truck. Keeping a generous gap behind a truck, and signaling early before braking or exiting, gives the driver more time to respond.

What should you do around wide turns and in heavy traffic?

Give turning trucks extra room, because a tractor-trailer can need a turn radius of 55 feet and often swings wide in the opposite direction before turning. A truck that moves left before a right turn is not signaling confusion. It is positioning the trailer so the rear wheels clear the corner.

Drivers who pull up beside the truck on the right at an intersection can get caught when the trailer cuts across the lane. Staying back behind the stop line, and never squeezing between a turning truck and the curb, avoids that trap.

In heavy traffic the same rules apply at slower speeds. Keep a larger gap in front of and behind a truck during stop-and-go traffic, signal early before changing lanes near one, and avoid hovering beside the trailer while looking for a gap. Work zones deserve special care, because lanes narrow, speeds change suddenly and trucks have less room to maneuver around cones and barriers.

Choosing a lane position where the truck driver's mirrors can see the car, or getting well clear of the truck, is the habit that matters most on every highway trip.

Final Thoughts on Sharing the Road With Big Rigs

Most crashes with big rigs start in a blind spot or a gap that was too small. Passing on the left without lingering, never cutting in right after a pass, giving trucks room to stop and turn, and staying where the driver's mirrors can see you remove most of that risk. LA Car readers who spend time on Southern California freeways share the road with trucks every day, and these habits make every one of those trips safer.