High Mount overhang

It depends on your overall length. If you can qualify as a traditional auto transport which requires you to be no more than 65 foot from front bumper of your power unit to rear bumper of your trailer, plus carry at least one vehicle on your power unit, then you are allowed 3' off the front of your power unit and 4' off the rear of your trailer. This is almost impossible to qualify for with the designs of modern trucks so almost no high mount actually qualifies as an auto transport.

High mounts that do not meet the definition of auto transports will not qualify for any overhang under Federal laws since the load is divisible, so there is no reason to have overhang in the eyes of the legislators, you can simply leave off enough units to not need overhang. This leaves high mount overhang up to the individual states, most of which do not allow any overhang. A few will allow it if you buy a permit, some allow front of trailer overhang, again each state is different.

Same rules for the straight trucks, the 5 pack and 4 car rollbacks are good examples. Some states allow overhang off a straight truck and lengths up to 45' while most restrict straight trucks to 40' bumper to bumper inclusive of load making 4 & 5 car straight trucks impractical for interstate routes.

When the Automobile Haulers Association of America (AHAA) was lobbying for the 80' stinger rule along with the gross weight increase that is needed to take full advantage of the extra length they compromised and didn't ask for any improvements to the high mount rules, since their membership is mostly companies that look down their noses at high mounts and run stingers. OOIDA is trying to have the rules changed to allow high mounts to be qualified as auto transports without the cab rack, which I believe is a step in the right direction but unlikely to succeed.

 

It truly depends on the state as to what they're going to enforce and not.

I have a 7 car high mount with a 1 car overhead rack. Im 74.5' tip to tail. The ONLY state I've had a problem is Iowa, $300 over length fine.

I run mostly Louisiana west into Arizona and north i to Colorado, but honestly never had a problem any where else. In TX it's 3' over front, 4' in rear flagged;
CO it's 3' front, 6' rear flagged with lights on at night if over 4' in rear.
The other states I run are more or less like TX.

Again, the individual state and or specific officer will determine what they will allow at the time they stop you and the mood they're in at the time.

 

Oregon is 53 ft trailer no flips, they don't care about over hang. Washington 53 ft no overhang or anything, can get a 56ft permit for 10$ for 30 days. Those are the only states I've been hassled in with my 7 car, and Florida you need to buy permit for car hauler trailer over 48 ft I believe it is which is also pretty in expensive to as well.

 

Last I remember, FL was $20 annually. You just had to order it online & they mailed out the permit. You also had to carry it in the truck. Think it may have covered 30" off of rear on the avg 53' trailer?