We all know there are a lot of regulations on cars. Automakers have to adhere to strict safety and emissions standards to sell their vehicles. With all that said, every once in a while, you’ll see someone driving a vehicle on the road that doesn’t look like it belongs there.

Sometimes it’s a big piece of farm or construction equipment, other times it’s a raggedy enduro motorcycle or some kind of trike, and occasionally you’ll see some kind of customized, Mad Max-style creation or a street-legal dune buggy. But how do those vehicles legally operate on the road when they’re so different than what’s typically for sale? It turns out, there are a wide variety of street-legal vehicles. 

There are Many Types of Vehicles Allowed on Public Roads

In addition to cars, trucks, SUVs, and vans, there are a wide variety of other vehicles that can be adapted for street use, including ATVs, golf carts, custom cars, most motorcycles, scooters and other motorized vehicles. Check out the video above to see an innovative street-legal trike made by Arcimoto.

With that said, there will usually be some kinds of restrictions on those vehicles as to top speed, engine size, and what locations they can operate in. Scooters and mopeds, for example, aren't allowed to operate on highways, and in most states, the engine displacement can't exceed 50cc.

Honda Ruckus
In most states, the mildly rugged Honda Ruckus would be classified as a scooter. (Image: Honda)

Classifications for what constitutes a scooter or moped can vary depending on the state, but typically a scooter has a platform for your feet and a moped has pedals. These traits along with its low engine power exclude it from operating along certain roads, and in some states, the vehicle can be ridden by people who don't have or have lost their license to operate other vehicles.  

Not every type of vehicle can be adapted for street use, and depending on the state and county you live in, you might find that the only thing allowed in your area is a typical car, SUV, or truck. That said, every locality is a little different, so it's worth checking. 

Laws Differ Depending on the Area of the Country

When it comes to the specifics of what can be legally driven on the road, turn to your state’s government. Each state has different laws for what makes a vehicle street legal. These regulations can not only vary depending on the state, but they also change according to vehicle type. Check out the video above put together by the South Carolina's Mount Pleasant Police Department to address the laws around street legal golf carts. 

motorcycle without turn signals and mirrors
In some states, this motorcycle's lack of two mirrors and turn signals would keep it from being street legal.

Many states have different requirements for motorcycles. A motorcycle that’s legal in one state may lack the equipment needed in another. Mirrors and turn signals are only required in certain states. The same goes for cars and other vehicles, too. California, for example, has stricter emissions standards than many other states. Even states with more relaxed emissions standards have different policies on how often or if ever a vehicle needs to get an emissions test done. Some states require regular emissions testing and others don’t.

There are also local laws that impact what’s legally allowed on the road. In a rural community, some exceptions can be made for certain ATVs, especially side-by-side vehicles like the Polaris Ranger. Mini trucks like some Japanese Kei trucks and vans can be legally operated on many roadways depending on the state and the area within that state that you live and plan to drive in.

Many Requirements are Similar Across the Country

California DMV
If you're curious about vehicle laws in your state, visit your local DMV office.

While it may come as a surprise that you can legally drive some odd vehicles on the road depending on the laws of the state and area you live in, there are some generalities among all states. Most have specific requirements for four-wheeled vehicles and a different set of requirements for two-wheeled or three-wheeled vehicles. Four-wheeled vehicles need structural items like a hood and body of a certain construction and certain safety gear like bumpers, lights, wiper blades, and a safety harness or seatbelt of some kind.

When it comes to two-wheeled and three-wheeled vehicles, the requirements can vary a little more, but still consist of a seat, engine requirements, and lights of some kind. There are also usually restrictions for what kinds of roads certain bikes can travel on, keeping underpowered vehicles off of major highways.

Bugatti Kit Car built by Pur Sang
Thanks to special kit car regulations, beauties like this Bugatti Type 33 replica can be made street legal.

Another commonality across state lines is the kit car, replica car, or custom car regulations. Most states allow for specially built custom cars to be legally operated on the road. These vehicles have to meet certain structural and safety standards before they are considered road legal.

This is how some drivers were getting the KTM X-Bow into the U.S. before it officially went on sale. While the vehicle will be sold as a track-only car, there are avenues through some of the kit car laws to get one registered for the road. The same can be said of the Ariel Atom. While the Atom is legal in Britain, it isn't totally legal in all 50 U.S. states. This means some buyers will have to find a workaround to get the model on the road. The kit car laws are a way to do that. 

The KTM X-Bow comes road legal abroad, but in the U.S. you have to register it as a kit car if you want to drive it off the racetrack.

On another note, three-wheeled racers, like the Polaris Slingshot or the Morgan 3 Wheeler are actually classified with motorcycles despite the fact you sit in and drive them like a car. This means they're much easier to register in most states because motorcycles don't have to meet the same safety requirements that four-wheeled cars do. This allows you get some impressive performance and some similar racecar-like looks without having to jump through the kit car regulatory hoops. 

While basically, every state has these kinds of laws, the specifics can vary dramatically. With all this said, we suggest you run down to your local DMV, to find out exactly what a motor vehicle needs to be street legal. Then you can start crafting your first home-made supercar in your garage.