The Fourth of July weekend is upon us, and with it, the great American tradition of the long road trip. Today, more pet owners than ever are foregoing the kennel in favor of bringing their furry friends along on vacation. How can you keep them safe on the road? Here, a brief guide:

Should dogs wear seat belts?

Yes. According to law enforcement officials and animal advocates, seat belt harnesses, car seats, and other forms of pet restraints make travel safer for everyone. An unrestrained pet is a "hazard," says St. Charles, Ill., Sheriff Patrick Perez, as quoted by The Wall Street Journal.

But why?

"If you are going 50 miles per hour and hit the brake," says Sheriff Perez, "the pet becomes a projectile in the car." In fact, research by Volvo indicates that a standard-sized dog traveling in a car at 30 mph turns into 2,700 pounds of force — the same size as a baby elephant. And while "the image of a happy dog hanging out of a car window is hard to top," says Gwendolyn Bounds at The Wall Street Journal, even that isn't safe. The smallest spec of flying debris could cause serious damage to your pet's eye or nose, says Petautosafety.com.

Seat-belted dogs make driving safer for humans, too?

Yes. A roaming dog leads to distracted driving, one of the reasons law enforcement officials are pushing for more doggy seat belts. A survey conducted by AAA reports that one-fifth of drivers allow their dogs on their laps. And even petting, or scolding a dog to "sit," distracts drivers from the road, creating dangerous situations.

Do most drivers seat belt their dogs?

No. According to advocacy group Bark Buckle Up, most families aren't taking the proper precaution. Last year, nearly 90 percent of pets traveling in cars weren't secured properly. Currently, there are no laws about harnessing pets in vehicles.

How do these harnesses work?

There are different kinds. Some companies, like Volvo, sell steel cargo barriers that keep pets confined to the luggage area of the car. Another option is booster seats, which hook around head rests and keep dogs secured in a basket-like container. Other harnesses attach to a standard car seat belt, with the other end secured around the dog's torso. A standard harness runs about $20 on PetsMart.com, with some sold as low as $6.79. Volvo's steel cargo barrier, however, is a bit pricier: $345.

Aren't they uncomfortable?

At first, most dogs will resist being harnessed, but once they get used to it, the seat belts "can actually be quite comfortable," says Petautosafety.com. With a car's change in speed, frequent turning, and sudden stopping, most dogs have a difficult time sitting or laying down. A secured dog won't have to brace himself against car maneuvers, allowing him to "lay down comfortably."

Sources: ABC 13 Petautosafety.com, PetsMart.com, Wall Street Journal