If you've got a big truck or SUV, chances are you have a step or side running board you use to help yourself get into the vehicle. Think about it -- if you need help getting in the car, your pet might need help, too. Pet steps and ramps may be a perfect solution.
Pet step and ramps are usually foldable to add to their portability when traveling by car or truck. In addition, ramps also come in telescoping models, where they expand and collapse within themselves for storage, or you can even buy a short ramp that doesn't fold at all. Those kinds of ramps are used on cars and very small SUVs for very small dogs or dogs that are older and need assistance entering and exiting the vehicle. You should also look for stairs or a ramp that has an anti-slip surface to protect your dog from slipping and sliding. Most ramps and steps will be adjustable and fit a variety of vehicles -- or even the steps of your house. The outdoor varieties can be used on decks as well as your car.
Though steps and ramps can be expensive, they are very sturdy, and might even be able to hold your weight. The properly made, heavy-duty varieties can hold up to 250 lbs.