If your dog is uncomfortable traveling in the car or you want to take your cat in the car at all, a pet travel crate is what you need -- and many agree it's the safest way for your pet to travel.

A pet trave­l crate, kennel, or carrier can come in a vast array of styles, colors and materials. They can range from utilitarian metal cages to decorative plush pieces. Aesthetics aside, if you're interested in safety, a hard-case carrier is probably the best option.

Though there aren't specific restrictions when using a particular crate in your own car, if you ever plan to fly with your pet, you may want to visit the airlines' pet crate requirements so you don't have to buy a second one down the line. For example, there are specific size requirements, and you can't use a wire or collapsible crate [source: Pet Relocation].

Even if you never plan on flying with your pet, you should buy within the following guidelines because you want your pet to be as comfortable as possible when traveling. When your pet is standing:

1. Measure from the tip of the nose to the base of the tail, closest to the hindquarters.
2. Measure from the floor to the highest point of your pet, either the head or the ears, if they stick up [source: Pet Relocation].

It's important that your pet can turn around, stretch out and relax in the crate. Conversely, a crate that is too big won't help either, as the animal may not feel secure. Take careful measurements and then purchase the crate closest in recommended size. Be sure it is properly constructed and allows for plenty of ventilation.