Training in Belgium ...
Belgium is full of miles and miles of great, cycling friendly and sometimes car-free roads to use for training. The best roads in Belgium for use with training are Canal roads which parallel the many canals. These roads are generally free of car-traffic and usually don’t require you to do much, if any stopping.
Also be sure that you always ride on the bike path if there is one, as this is required by law. Sometimes the path is even on the wrong side of the road, but is still wide enough for two way bike traffic.