The U.S. Department of Transportation (DOT) says, “No state shall impose…a rear overhang limitation of less than four feet.” Therefore, four feet is the minimum allowable, and individual states set different maximum limits. In some cases, what overhang is legal on a vehicle depends on the items being transported. Some laws allow longer lengths when the items can’t be easily disassembled or shortened.

What is the legal overhang on a truck?

Whether you’re concerned about the legal overhang on a truck or the legal overhang on a flatbed trailer, the answer is the same. It varies by state, but the rules tend to fall into a few implementation methods.

  • Following DOT rules to the letter: This means the DOT’s minimum limit of overhanging four feet from the rear is also that state’s maximum limit.
  • Expanding on DOT’s limits: Some states allow a longer limit on any item extending beyond the rear of the vehicle.
  • Setting different limits for different items: Some states allow longer overhang limits for items that can’t be easily disassembled or shortened such as long metal poles.
  • Limiting the vehicle length instead of the overhanging items: Some states say it doesn’t matter how long the overhanging items are, if the vehicle’s total length, including the overhang measurement, doesn’t exceed a set limit.

These rules also apply to how far something can extend from your car as well. Check with your state’s Department of Motor Vehicles (DMV) for their specific rules.

Long load flag requirements

Although not all states require them, consider red flags for long loads to alert anyone approaching you from the rear to the material extending out of the back of your vehicle. For states requiring drivers to tie a flag to the back of the item overhanging the truck bed, additional rules may cover various flag aspects, including:

  • Length of overhang that requires a flag
  • Size and shape of the flag
  • Allowable colors for the flag
  • How the driver must display the flag
  • Minimum distance from which other drivers can see the flag
  • Replacing the flag with a light or lamp during nighttime driving

Check with your DMV – and that of any other state you may be driving through – to find out about long load flag requirements and oversize weight load requirements.

Tips for driving and sharing the road with long loads

Trailer overhang regulations don’t generally say anything about using your flashers or hazard lights while carrying a long load. But it’s another useful tool for calling attention to a long load for the vehicles behind you. You may not need to drive more slowly than the posted speed limit. However, staying in the right-hand lane when possible, taking turns carefully, and minding your turning radius are good principles to follow.

If you’re driving on the road near a vehicle with an overhanging load, be sure to give that vehicle plenty of space. You don’t want to crash into the extended load if the car comes to a sudden stop. And if you’re about to pass a vehicle in the act of turning with an overhanging load, make sure you stay back far enough to avoid getting side-swiped by the load as it turns.