To answer the thread title, I do look for right turn only loops when I actually want to train. For example I used to do regular rides in downtown Stamford, doing a sprint on one side of the 2 mile loop. The loop has all right turns, has either a median or is on one way roads (no oncoming traffic) and only one turn is a no turn on red. However there's a sidewalk there and since it's legal to ride on sidewalk at under 15 mph, I'll hop onto the sidewalk before that intersection and ride around the corner.

Although I've been pulled over on that loop while on my bike, it wasn't for violating a red light or the like.