I commute 5 miles to university on a two-lane-each-way main street in a small Utah city, speed limit 40MPH, and 30MPH in the center of town. Today a cop pulled me over.

Cop: You should ride on the side, to the right of the right lane.

Me: But that's the shoulder

Cop: It's not a shoulder, it's for parking.

(So what's it called so I can check what the traffic code says about it?)

Cop: You're going too slow, you're impeding the flow of traffic.

Me: I'm part of the flow of traffic.

Cop: But you're slowing people down. If you can't go the speed limit, you should stay out of the lane.

Me: There's room in the lane for them to pass me, they just weren't.

Cop: People are going too fast for you here. I don't want to scrape you off the street.

Me: What should I do when I get to the center of town, where cars are parked on the side?

Cop: Traffic is slow enough (people driving 35MPH, instead of 45) that you should be OK. But you are supposed to have lights and mirrors.

Me: Isn't that just for night:

Cop: The lights are, but you're supposed to have mirrors.

Me: I don't remember anything in the traffic code about mirrors, but OK.

Is it illegal or unsafe to ride in a lane when I can't go the speed limit? If I were in the area he wants me to ride, I'd be more concerned, because drivers don't scan that part of the road. If I went straight at an intersection, I'd be concerned about a driver turning right without looking. And I'll be checking the law for mention of mirrors. Maybe I should get one anyway.