There are many kinds of vehicles that are considered off highway vehicles (OHVs). The term most often is used regarding dirt bikes, ATVs, ATCs, side-by-sides (Utility Task Vehicles or UTVs), dune buggies, and 4x4s but could also be used to describe snowmobiles and personal watercraft. Technically, mountain bikes and even off-road skateboards could be considered OHVs, but the term is usually applied to motor powered vehicles. You ride dirt bikes, ATVs, ATCs, Jetskis, and Snowmobiles, straddling a seat or saddle and using handlebars. You drive UTVs or side-by-sides, dune buggies, and 4x4s, sitting in a seat (with seat belts) and using a steering wheel. In most places you must be licensed driver at least 16 years of age to drive a UTV, dune buggie, or 4x4. Laws regarding dirt bikes and ATVs vary from state to state.
Dirt bikes are off-road motorcycles. They have two wheels. They are rated by engine size and typically range from 50cc to 650cc. Dirt bikes are the most difficult land based motorized OHVs to learn to ride. Like riding a bicycle, you must learn to balance the motorcycle to keep it upright but the engine provides a gyroscopic effect that gives some assistance. They are popular for riding single track trails and have the capability to ride on trails that cross slopes without falling over (unless the rider is careless or incompetent). An advanced form of dirt bike is the motocross bike. These are specially equipped and tuned for racing on motocross and Supercross tracks but you will often see them ridden by recreational riders on the trails. They are fast and powerful and capable of performing many stunts, such as wheelies and jumps in the hands of an experienced rider. Dirt bikes are usually designed to carry only one rider but some are or can be configured to carry an additional passenger with the addition of a second set of foot pegs and an extended seat.
Early motorcycles were, by necessity, off road machines, or, more correctly using today's language, dual sport machines. The lack of developed roads in the early 20th Century meant most vehicles had to be capable of at least some off road operation. The first dirt bikes specifically for off road riding and racing were custom made by riders themselves from Triumph and Rickman street motorcycle components starting in the 1940s. Then, seeing a potentially profitable market, Japanese companies like Honda, Yamaha, Suzuki, and Kawasaki started manufacturing factory dirt bikes for retail sale. A friend of mine bought the 2nd Yamaha IT 400 sold in the United States and we owned it for several years. Other prominent brands include KTM (Austria), Husqvarna (Sweden), and ATK (United States). Dirt bikes are made for riding in the the dirt. If you must ride on pavement, exercise extra caution. The knobby tires are not designed for use on pavement and could cause an accident. Dirt bikes are normally not legal to be ridden on paved roads but can sometimes be "dual sported" to qualify for occasional street use. There are special "D.O.T." knobbies that are street legal, but as with most compromises, they aren't as good on the street as normal highway tires nor as good in the dirt as off road tires. ATV tires are especially dangerous on the road. Ive read that most ATV accidents occur on paved roads and some of them have been fatal. Pavement isn't as forgiving as grass or dirt
ATCs (All Terrain Cycles) were predecessors of the ATV and have 3 wheels. They are sometimes called 3-wheelers. They were only manufactured and sold for a few years due to purported dangers associated with them. It is often thought they were banned in the United States by Federal law. In reality, the threat of a Federal ban caused the manufacturers to impose their own moratorium in accordance with a consent decree during which they turned their attention to 4-wheel ATVs. You can still find a few pre-owned ATCs around, but new ones have not been sold in the United States since the mid 1980s. There were some inherent design features that were blamed for a number of accidents, some of them fatal. Some notable examples are: running over your own foot with one of the rear wheels (I NEVER did that with my dirt bike!) and the perception that their 3-wheeled tricycle format made them easy to ride. The latter often drew young or novice riders who quickly exceeded their personal limits and found themselves in serious trouble. Another anomaly that gave inexperienced ATC riders problems was that, unlike bicycles and motorcycles, leaning into a turn could cause you to turn the opposite way! For example, leaning left would transfer extra weight onto the left rear wheel, giving it more traction and causing it to move forward faster than the right rear wheel, forcing the ATC to turn right regardless of which way the front wheel was turned. Manufacturers steadfastly denied that ATCs were inherently more dangerous than dirt bikes, but the public perception of their faults led to government investigations and ultimately to the demise of their production. Contrary to popular belief, they were never outlawed. Rather, a voluntary moritorium was implemented by the manufacturers to avoid legal restrictions. By the time the moratorium had expired, manufacturers had replaced their 3-wheeled ATCs with 4-wheeled ATVs, which were much more stable, and had no interest in reviving the much-maligned three-wheelers. If you should find one in good condition it can be fun to ride. Just be aware of its limitations and idiosyncracies! I suspect building machines with 3 wheels was less expensive than building them with 4 wheels so 3-wheelers came before 4-wheelers.
ATVs or 4-wheelers are 4-wheeled off highway vehicles that replaced the ATCs. They are popular as recreational toys and as working utility vehicles on farms and ranches and in the forest. Many are equipped with 4WD making them capable of negotiating low traction situations like mud, sand, and snow. Their stability lends them to search and rescue operations, both for carrying gear and transporting patients.
Side-by-sides or UTVs are kind of like a large ATV or a small 4x4, depending on your perspective. They get their name from the seating configuration that puts at least 2 people sitting side-by-side as they would in a Jeep or a sports car. Larger units may have 4-6 seats. You steer them with a steering wheel, just like a car. All side-by-sides I've seen have 4 wheel drive, bu there some 2WD models. They usually provide a quite comfortable ride, with wheel travel that rivals dirt bikes. The larger units are sometimes prohibited on ATV trails because of their additional width. Being larger and more complex, they can be significantly more expensive than dirt bikes and ATVs, but if some of your party is happy riding as a passenger instead of operating the vehicle themselves, they might be cost effective. For example, one UTV can could carry 4 people and may cost less than 4 dirt bikes, depending on the model and optional features. Some popular examples of side-by-sides are the Yamaha Rhino, the Kawasaki Mule, the Polaris RZR, and the Arctic Cat Wildcat. Like ATVs, side-by-sides are often used as utility vehicles for farm and ranch work. In fact, the Kawasaki Mule was at first a farm and ranch utility vehicle that users adapted for recreational use. UTVs are fairly stable on pavement but driving them on paved roads for any distance will cause premature tire wear. They are not typically licensed for on road operation.
Dune buggies are another form of off highway vehicles that can provide a lot of family fun. There are two basic styles of dune buggies I am familiar with: rails and fiberglass bodies. Most are built on Volkswagen or Corvair chassis The rear-mounted, air-cooled engines seem particularly well suited to dune buggies. Rails typically have one or two bucket seats while fiberglass body version usually seat 4 people comfortably and safely. I once owned a Corvair-powered dune rail and had the privilege of driving the fiberglass bodied dune buggy used by Steve McQueen in the Thomas Crown Affair. It belonged to one of my dirt biking buddies.
4x4s typically used for off road recreational purposes include the venerable Jeep, which found its first service as a general purpose military vehicle in World War II and many 4 wheel drive pickups. Many of todays SUVs also come in a 4 wheel drive configuration that is sometimes used for off roading. Because of the size of these vehicles they are unable to travel on designated dirt bike or ATV trails but are excellent for riding fire roads and other unimproved roads. Some 4x4s are modified to be "rock crawlers", who compete in rigorous events challenging the ability of machine and driver to climb over large boulder and ascend steep, rocky slopes. A popular option on many 4x4s (especially rock crawlers) is a power winch, which can be used to pull the vehicle through especially difficult terrain and pull it out if it gets stuck. Since many 4x4s are modified highway vehicles they often are street licensed.
Mountain bikes are sometimes considered off road vehicles and are banned from designated wilderness areas and many hiking trails. Properly equipped mountain bikes in the hands of a competent rider can handle remarkably difficult terrain. Forest and desert trails are popular venues for mountain biking. The "slick rock" area around Moab in south eastern Utah is one of the most famous places for mountain biking. Mountain bikes often share dirt bike trails in many locations.
Snowmobiles are an off highway vehicle for winter use. You ride them kind of like an ATV, sitting on the saddle and steering with handlebars connected to skis up front. The drive is provided by a single, center mounted. tank type rubber track that gives excellent traction in the snow. Snowmobiles come in at least two major categories: trail machines and powder machines. Trails machines are ideal for use on groomed snowmobile trails and roads but if you want to go cross country and make your own trails, you'll probably want a powder machine. Powder machines are usually bigger and more powerful so trail rated machines are best for beginners. Beginners would do well to seek out groomed snowmobile trails until they gain sufficient skills to venture off the trail.
Jet skis and other personal watercraft are sometimes included in the category of OHVs, but in common usage OHV usually pertains to land toys. Jet skis are sometimes called "wet bikes", connoting that they are similar to dirt bikes for the water. They are, in fact, ridden like a motorcycle, straddling the saddle or seat and steering with handlebars.
Tracked OHVs. Some years ago there was a cute little tracked OHV called a
Trackster. It was manufactured by
Cushman, who is better known for their motor scooters. Tracksters are no longer manufactured but there are still a few around if you search for them. The tank-like tracks give them incredible off road capabilities -- in dirt, sand, mud, and snow Tracksters can go just about anywhere. My uncle, who was a dealer for them when I was in my teens, took us for a ride up a steep set of hundreds of concrete steps to the top of one of the benches near his home. It was quite a ride! There are a few specialized ATVs or specially modified ATVs and side-by-sides that ride on tracks and you can even by track kits for larger 4x4s. These kits usually replace each wheel with a triangular track that has its own 3 wheels. For normal driving the track rotates around all three of its wheels but when climbing over an obstacle the whole assembly may rotate, giving the vehicle ability to climb over things like rocks and logs. Track kits are relatively expensive so you will probably need a very good reason for converting your 4x4.
There are track kits available to convert ATVs, UTVs, and other 4x4 vehicles and even dirt bikes from wheeled to tracked format. They are fairly expensive but are promising adaptations that could expand the capabilities of wheeled off road vehicles. Tracked vehicles can often traverse difficult terrain and obstacles that would stop a wheeled vehicle. There are even track conversions for dirt bikes.
Personal safety is an important consideration for all OHV activities. First of all, make sure your machine is in good condition and that none of its factory installed safety features have been removed or disabled. Second, get appropriate training and practice to ensure you can safely operate the machine. This means more than just being able to move in a straight line and negotiate turns. You need to understand the capabilities and the limitations of your equipment as well as your ability to control the machine. Last but certainly not least, wear appropriate Personal Protective Equipment (PPE) and correct use of safety devices (such as seat belts on UTVs). The PPE you need will depend on the type of vehicle you're riding. I strongly recommend full body armor for riding dirt bikes, ATCs, and ATVs, and at least helmets and goggles when riding UTVs and 4x4s. Personal water craft require appropriate, US Coast Guard approved flotation devices. One final bit of advice: those cool tricks you see in the Supercross, X-games, or during other televised off-road events, are performed by professional riders with years and years of special training and their equipment usually includes significant modifications to enhance both performance and safety. Don't try to imitate their antics! Performing an incredible stunt may look like fun, but without proper training, experience, and equipment, it is likely to have extremely painful (possibly fatal) and very expensive results.
Have fun off road!