I live in a very busy city quite far from city borders and our roads outside the city are real gas chambers for the first 10-20 km. I don't have time to get to cleaner places so I'm choosing to train using loops around blocks near my block of flats (the furthest is about 8 km from home), moreover I mostly ride them late in the night when traffic abates to reasonable level. I've invented loads of loops from 2.27 km to 12km avoiding suffocating major streets. Initially I often got bored with riding lap after lap on the same course but I'm getting more and more used to it. Some are flat, some are hilly (for the place where I live) thus I can vary load and degree of boredom. I wonder if I'm the only one using such training tactics or there are other straggling riders and if so what length are you loops and how do you feel riding them? Fun, joy, self-pity?