Cyclocross bikes have sligtly shorter frames and higher bars than road bikes. This gives a more relaxed ride position. They also have fatter tires which are more forgiving on less than perfect roads. Touring bikes are similar but tend of be heavier for load carrying. Both of these have the drop bars that offer multiple hand positions. I am 68 and bought a Swagman hitch rack a couple of years ago. It makes it a lot easier to put the bike on the car than a roof rack, but it is a lot heavier than a trunk mounted rack, if you have to consider taking the rack on and off the car.