It is illegal to drive a bicycle in the travel lanes of Interstate highways, but you can use the shoulder if there is no service/feeder road. I don't like riding the shoulder or the service roads, because of cager ragers, but riding the service roads is the major route to town where I live, and in many towns here (North East Texas), it is popular and common to ride on the feeder/access roads, especially in large pelotons.
If you ride on Interstate shoulders, you run into a lot of hazards: errant drivers, glass and debris (including dead cars, couches, auto parts and tire peelings), intersections (on/off ramps), road signs and markers (those egg shaped yellow things or reflectors), salmoning cyclists (rare on the shoulder of freeway but I've encountered them), and emergency vehicles and cutting drivers when traffic backs up below 25mph.
Originally Posted by omnivox42
I dont think cycling on the interstates are legal in Texas. ( I may be wrong). I have rode on a highway (highway 90) and had no issues with Johnny law. I see people biking there often. It has a HUUUGE shoulder. I think the difference is the lack of entrance/exit ramps, over passes, and 65+ mile an hour speed.