New Route
 

So I live in a rural area. Most of the roads are hilly "backroads" with no shoulder, on which I've been riding.

There is the main state route that goes through town. It's a three lane road; one lane going east, one west, and the middle turn lane. The speed limit is 55 mph. There are 5 foot shoulders on each side, and the road is straight and fairly flat for miles. I'd like to ride this road for speed work.

I'm hesitant to ride this road mainly because I never see fellow cyclists on it - it could be because there's a lower population of cyclists in the area. I see no biking prohibited signs. Are there town ordinances that I need to look into for riding this state route - or is my hesitancy unfounded? Do any of you ride roads with a 55 mph speed limit? Anything of which I need to take special caution or consideration?

I ride on narrow 55mph roads with no shoulders...it ain't no big thing as long as you are visible, ride predictably & courteously and are aware of the speed differential. Having a shoulder to ride in doesn't change that.

hesitancy is unfounded

Higher speed limits = less reaction time + more injuries. So your worries are not unfounded. However chances of being smacked into are still extremely low.