New Driver’s Guide to Trucking

Thinking about a driving career? New to the industry and looking for real-world information about trucking? This is the place. You’ll learn some stuff and I won’t try to sell you anything or push a truck driving school. Tips, what to expect, and the truth about the business. Good or bad.


New Driver’s Guide to Trucks and Trailers

If you’re new to trucking or thinking about a driving career, you’ll run into a lot of confusing industry jargon; starting with all the different types of trucks and trailers on the road. Understanding the various types of equipment used in the industry might help you find a career you didn’t know existed. First, some words and phrases for new drivers to avoid.

Things Truck Drivers Shouldn’t Say: Box Truck, Semi, or Big Rig

Terms like box truck create confusion. A truck built on a single frame should be called a straight truck.

Image via Flickr by Jason Lawrence

Don’t use the words semi or semi-truck. Semi is short for a semi-trailer, which is a trailer that does not have a front axle. The trucking industry only uses semi-trailers. When not hooked to a tractor, the front of the trailer rests on two retractable supports called landing gear.

Image via Flickr by grabadonut

Along the way, a semi came to mean the tractor instead of the trailer to some. Others confuse semi-truck with a tractor-trailer combination. A semi-truck is a tractor that is pulling a semi. See? Confusing.

Use the words tractor and trailer to avoid ambiguity. A tractor is also the power unit, usually shortened to unit; as in, “your unit is due for maintenance.” While the term big truck is commonly used to describe tractors with a sleeper berth, big rig is not.

Another quirk of industry lingo is that dual axles on a trailer are called tandems, but dual axles on a tractor are not.

Axles, Bobtailing, and the Difference Between Left and Right

The driver’s side is the left side. You’ll have to use left and right correctly on daily pre-trip inspections, maintenance records, and to report problems such as flat tires.

The front axle is the steering axle and the front tires are steering tires. So, you would report a flat on the driver’s side front axle as the left steering tire.

The rear axles of a tractor are called drive axles. A tractor with only one rear axle is a single axle or single screw. Single axle tractors can’t carry as much weight as dual axles and they do not have sleeper berths. Because of their smaller size and better turning ability, they are easier to navigate in tight areas though. A single screw tractor hooked to a trailer cannot be called an 18-wheeler because it only has 14-wheels total. Either way, the term 18-wheeler isn’t used in the business.

When hauling cargo ­(pulling a load, under a load, or just loaded) ­you will often have to scale your truck before the freight is loaded. This is called a tare, or empty, weight. After loading is complete, the truck is weighed again. This is the gross weight. Subtracting the tare from the gross gives you the net, which is the weight of the cargo only.

After driving a truck onto the scale, weights are taken separately for the steering axle and each set of drive and trailer axles. The Federal Highway Administration explains weight limits in detail. Scales are available at many truck stops and a few customers have their own.

A tractor that is not connected to a trailer is bobtailing. You may hear a driver say, “I’m bobtailing to the yard to grab an empty.”

Image via Flickr by Frank Deanrdo

Drop and hook is another term you’ll hear a lot. Dropping a trailer means disconnecting from it and leaving the front end to rest on its landing gear, usually backed up to a dock or left on a lot to be loaded or unloaded later.

Hooking means backing a bobtail tractor underneath a trailer so that the fifth-wheel and kingpin (more on these later) lock securely together. Airlines from a compressor on the tractor are attached to couplers on the trailer to supply it air for braking and other features. A cord called a pigtail transfers the electricity needed for trailer lights.

Different Types of Tractors

Tractor with refrigerated trailer at loading dock.
Big truck with a refrigerated trailer backed into a loading dock – image via

A tractor with a sleeper berth is also called a big truck, road truck, or road unit. The berth, or bunk area, is the section behind the front seats. The tractor shown above is a typical size but some are considerably larger.

Long-nosed tractors for example. As the name implies, the hoods of these trucks are longer than the scooped hoods (anteaters) shown above, and they are more squared. Some long-nose trucks have an extra-large sleeper berth called a doghouse that can be extravagantly outfitted.

The larger a tractor is the less maneuverable it is though. Once you venture away from highways, truck stops, and distribution centers there are places that tractors this large, pulling a 53-foot trailer, cannot access that a smaller tractor can.

In the moving industry, long-nosed trucks are known for not being able to access some residential areas and building complexes. Regardless, there are drivers who believe a long-nose Peterbilt or Kenworth are the only trucks worth driving.

Most sleeper cabs have enough headroom to stand up and move between the bunk and cockpit areas, plenty of storage space, spots to secure a TV and refrigerator, separate speaker and air conditioning controls for the berth area, and built-in cabinets for drawers and closets.

Day Cabs

These tractors do not have sleeper berths and are used mainly for local or regional work. Drivers in day cabs are either home every night or stay in a motel. Hence the name day cab. They can be a single or dual axle.

An accurate model of a day cab cabover with its cockpit tilted forward to access the engine compartment. A metal disc above the single rear axle is the fifth-wheel. The trailer's kingpin locks into the slot in the middle.
Image via Flickr by Bill Abbott
This is a toy, but a very accurate model. It shows a day cab cabover with its cockpit tilted forward to access the engine compartment. The metal disc above the single rear axle is the fifth-wheel. The trailer’s kingpin goes into the slot in the middle and locks until released.


The word cabover literally means that the cab is built over the engine. With most trucks, the cab sits behind the engine compartment and a hood swings up and out to access the motor, similar to a car. To access the engine of a cab over, the entire cab tips forward; and anything that is not secured goes with it.

Cabovers were never popular with American drivers. The sleeper berths are small, and they are known for rough rides and mechanical problems. Their popularity outside of the US is because the flat front and shorter design of a cabover increase maneuverability, and they are less expensive. Infrastructure in much of the US is relatively new compared to that of Europe, for example, so navigating in congested areas is more of a concern there. In the US, the Northeast and some Midwestern cities are challenging for drivers, but newer infrastructure is mostly designed to accommodate modern trucks.

Some cabover models used to, and may still, have a valve in the engine compartment that must be manually turned to switch from heating to air conditioning and back. The cab has to be tilted forward to access the valve. When driving thousands of miles a week thru different climates that valve can really piss you off.

Yard, Terminal, and Spotting Tractors -They’re All the Same Thing by the Way

When trailers are loaded or unloaded at warehouses and distribution centers they need to be moved in or out of docks as soon as possible to get the next trailer in and keep the work going. On a large scale, this means employing “yard dogs”. Despite the derogatory nick-name, which many employers forbid the use of nowadays, it’s a fast-paced and demanding position.

Spotting tractor, terminal truck, or yard jockey are acceptable terms, and the operators of these vehicles are called spotters or jockeys. Spotting tractors are built specifically to move trailers around in an enclosed area. They rarely leave the yard or lot but can be street legal to go short distances. Designs vary, but they all do one important thing; enable spotters to drop and hook trailers quicker.

Some have a door in the rear and a metal grate for the spotter to stand on to reach the airlines and pigtail. The most important feature of spotting tractors is that they allow an operator to raise a trailer so that it’s tilted up at a slight angle and can be moved without having to raise and lower the landing gear. Trailers are less stable when moved this way and it must be done carefully. When there are dozens, or hundreds, of trailers to jockey every shift terminal tractors save a lot of time.

What are Fifth Wheels and Kingpins?

You’ve seen bobtail tractors before and noticed a big metal disc with a slot down the middle above the rear axles (see image of toy truck above). This is the fifth wheel. The trailer’s kingpin, a stubby steel shaft that juts down from underneath the front of a trailer, slides into the slot on the fifth wheel and latches into place. This is how trailers are secured to trucks and it is very safe if done properly with well-maintained equipment.

A trailer needs to be sitting a little lower than the rear edge of the fifth wheel so that as the tractor backs under the trailer and fastens to the kingpin the trailer is lifted slightly. Fifth wheels tilt up and down to act as a wedge to get underneath trailers. Sometimes it takes a little throttle power to back under a trailer with a heavy load. When the front of a trailer rests securely on the fifth-wheel, the landing gear will easily crank-up now that the weight of the front end of the trailer is transferred to the tractor.

Cab Under

These are rare, probably no longer made, and only appear to be in use in parts of the Northeast. Cab under means that the cab area is below the sleeper berth. There is a hatch that opens above the driver’s area to crawl up into the sleeper berth. Good riddance to the cab under.

Gross Weights and Lengths

All cars, trucks, and trailers have a have a Gross Vehicle Weight Rating determined by the manufacturer. The GVWR is the maximum safe weight of a vehicle including passengers and cargo. Most people don’t think twice about the GVWR of their cars; but in the trucking world, it is an important number. For instance, the GVWR of a standard tractor-trailer combination is 80,000 lbs., 34,000 lbs. each for the drive and trailer axles. The steering axle carries the balance of the weight.

The maximum trailer length, without a special permit, for a single trailer is 53′. The de-facto trailer height limit, from the ground up, is 13′ 6″ but there is no federal limit. The overhead clearance of bridges and other infrastructure dictates the height of trucks

Straight Trucks

A straight truck with a GVWR of over 26,001 lbs. requires a Class B CDL (Commercial Driver’s License) to operate. Moving van rental companies, like Uhaul, keep the GVWR of their public fleets below that. Otherwise, customers would need a Class B to drive them.

The cargo area of most straight trucks that require a CDL to operate is 24’ to 28’ long. Box heights vary with design and purpose but must also be under 13′ 6″.

There is no federal length limit for straight trucks, but most states allow a maximum of 40’ and only a few permit more than 45’. Some straight trucks have two axles like a car, but the rear axle will have four wheels to handle the weight of cargo. Larger straight trucks, and those built to carry small but heavy loads, usually have two rear axles.