Ramps for dogs are excellent tools for travel, but they are versatile and can provide other functions as well.
Things to consider:
Versatility - Ramps are not only for dog travel. Consider using your dog ramps indoors too to help your small, arthritic, or senior dogs to be able to more easily climb on and off permissible furniture. You can also use them outdoors to help these same dogs get on and off decks and porches.
Ramp Training - The first few times you try to train your dog to utilize his ramps, he may be resistant. To make the experience both fun and effective, place some dog treats at various points along the ramp, with nice dog chews or dog toys at the very top as his final reward. Before long, you will not need to use them, but you might want to have something nice for him to enjoy once he is in the vehicle anyway.
Easy Climb - Do not make your senior dogs or arthritic dogs have to jump up to get into the vehicle. Moreover, do not bust your own hump trying to lift them in. Just train them to use convenient, portable ramps. If your dog are taking out for a spin, you will be able to secure him safely behind his indoor car barriers.