Travel trailers are the most popular type of non-motorized RV. They come in all sizes, including tiny jelly bean-shaped models with a chuckwagon kitchen in the rear to a complete house-on-wheels with multiple slideouts and residential-sized appliances. Sometimes called a “bumper-pull” (when they first became popular in the early ‘50s, they were attached to the bumper of the tow car), the modern travel trailer employs a hitch secured to the frame of your tow vehicle, along with specialized hardware to make towing safe and easy..