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When a typical American hears the word “jeep”, they immediately think of the iconic 4-wheel drive utility vehicle. These stalwarts represent the golden era of ingenuity which encompassed the United States before and during the Second World War. The article this week is not about sport utility vehicle jeeps, but rather a different kind of jeep used by the specialized transportation industry.

A couple weeks ago, the ITEA published an article titled Axle Folly. In narrative was an explanation about how increased numbers of axles protect the integrity of road surfaces with increasing weight. Physics is physics, and a single vehicle (truck or trailer) can only have so many axles on the ground before it will be unable to turn at all.

The most customary vehicle configuration in the heavy haul industry is the semi-tractor semi-trailer. It is not uncommon to find 4-axle tractors towing a 4 or 5-axle semi-trailer to accommodate a heavy load. The problem is what to do when the load weight exceeds that which can be safely and lawfully carried on 8 or 9 axles?

Jeeps. That’s the answer! Sometimes jeeps are also referred to as “jo-dogs” or “dollies”, but in truth they are all auxiliary load dividing axles. Jeeps are vehicles in and of themselves, and added inline to a string of vehicles to spread the load out.

What makes jeeps so invaluable to the heavy hauler is that not only do they increase axles, but they also provide another point of articulation. This makes cornering easier for the driver.

Sometimes carriers will pin extra axles on the back of trailers to also spread the load out, but what makes jeeps interesting is how they are coupled. Each jeep has a kingpin which locks into the 5th wheel of the vehicle ahead of it. The jeep extends the length of the vehicle with one, two, three or sometimes four extra axles. At the rear of the jeep is another 5th wheel which the next trailer locks into.

There are typically two questions law enforcement or truckers in Illinois have about jeeps…so here are the answers:

Question: Does the driver operating a combination of vehicles with jeeps required the double/triple trailers endorsement on their CDL?

Answer: Yes. This is plainly spelled out in the guidance section of Part 383 in the Federal Motor Carrier Safety Regulations.

Jeeps are vehicles, and more specifically trailers. When a truck or tractor is towing two or more trailers (there are exceptions of course), the driver must have the double/triple trailers endorsement on their CDL. This endorsement is represented by the letter “T”. In order to obtain a “T” endorsement, the CDL holder must pass a written knowledge test with the Secretary of State.

Question: Do jeeps make a load “divisible” thereby voiding an overweight permit?

Answer: No. This is a really great question though! If one reads the definition of a non-divisible load in 625 ILCS 5/1-148.8, a jeep wholly fits the definition: 1.   By not having the jeep, the intended load is not compromised. 2.   By not having a jeep, the load is not destroyed or unable to be used. 3.   It definitely does not take more than eight hours to disconnect it.

Here’s the rub to that argument. Many times combinations of vehicles involving a jeep, or multiple jeeps, are overweight without a load. The combination delivers an overweight load and returns empty on an overweight permit.

If the combination could be considered divisible when it’s unladen, would it not stand to reason the combination was divisible when laden as well? Would not that void the permit, allowing the vehicles legal weight only, laden or unladen?

If this argument was valid, then there would be a ceiling as to the maximum number of axles which could fit on one tractor and one trailer. This would then create a maximum weight of any load, far less than what is carried now using jeeps.

Jeeps are standard and customary vehicles designed to protect the infrastructure when the heaviest of loads are carried. They are non-divisible.

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