There is a lot of good advice on here. I would never call it a day but would certainly pay heed to many of the contributors. Use road position positively to signal your intentions. At the same time, know when it is better to withdraw: sitting out on a verge for ten minutes at a crazy roundabout can be all it needs for conditions to improve from death-wish to life-enhancing. In general, common sense and a refusal to get caught up in other people's mindlessness does the trick. For me, there is an underlying advantage in being out on the road: no one is piping music at you. Gyms feel like prisons to me; anonymous people constrained to hard labour in dreary conditions oppressed by somebody else's taste in music that runs to rhythms that my body simply never recognizes. Each to his or her own, but the open road for me every time.