Why You Should Avoid Passing A Semi Truck On The Right

Unless you're always using minor roads and back alleys, you're bound to encounter semi trucks when out driving. They're not necessarily a hazard, but you have to keep in mind that sharing the road with such huge vehicles requires some extra attention. That's because there's a large difference between the blind spots of a semi truck and that of a smaller car. Sure, some cars have bad blind spots, but a semi truck's are even worse. 

Commercial trucks have highway speed restrictions that make passing them tempting, but the rule of thumb — whether you're passing a regular car or a massive semi — is to only overtake on the left. However, it's especially important to apply this rule with semi trucks. The blind spot to a semi driver's right is much larger than the one to their left, and you'll be out of sight and in danger for at least several seconds. It's even illegal to pass any other vehicle on the right in many states.

Blind spots, also called no-zones in a semi truck, are present on all four sides. The front no-zone extends up to 20 feet from the vehicle and is primarily due to the driver's seating position relative to the high, long nose of the tractor. These circumstances effectively hide smaller cars hanging out too close in front. Meanwhile, the rear no-zone measures 200 feet from the back of the trailer. Because semi trucks don't have rearview mirrors and their trailers would block the view anyway, drivers have no way of knowing whether someone is directly behind them.

On the left of the semi truck, there's a no-zone covering a single lane. It starts from the side of the tractor and stretches out to almost the midpoint of the trailer. The right side of the semi truck also has a no-zone, and it's considerably larger than the others. It covers two to three lanes and has a length of almost the entire trailer. When the semi is turning right, this right no-zone even extends a few feet in front of the vehicle.

Understanding these no-zones is a crucial part of driving near semi trucks. If you're not careful, you can be seriously injured or killed. In fact, these blind spots are where a third of fatal car and semi truck crashes happen, according to the Arizona Trucking Association Foundation. You should never pass another vehicle on the right, but here is some guidance on how to pass a semi-truck without incident. It's important to complete the pass as quickly as you can so you're in the no-zones for as little time as possible. Signal before moving alongside the truck, and accelerate smoothly until you're well clear of it.

 When you need to change back to the truck's lane after making a successful pass, don't just cut in front of them. Semis are heavy — Tesla semis can carry 82,000 pounds, for instance — and need far more room than cars to brake. Before changing lanes, look at your rear view mirror to make sure you can see the entire truck, including its wheels. This means you're out of the front no-zone. Only then is it safe to slide over in front of the truck. After changing lanes, accelerate even further away from the semi to help keep the driver at a safe following distance.

If you're on a descent with a semi, they'll usually speed up a little. It's best not to overtake here and wait until you get back to where conditions are better for passing. The same goes for curves, locations with traffic or railroad signals, or approaching a congested area. Even if you have time to make a complete pass, switching back to the truck's lane and slowing down abruptly could mean trouble.

In case you can't safely overtake safely, a good place to wait is in the lane to the left of the truck at a minimum following distance of 200 feet. Never tailgate a semi or linger in its no-zones. If you're unsure whether or not you're in a blind spot, just remember this rule: you should be able to see the semi operator's head and/or the driver's side mirror from where you are. Otherwise, you're likely in a no-zone where the driver won't notice you.