I generally do 13 miles each way, with the shortest possible route being just under 5 miles. Im quite fortunate with my commute, once Im out the city (about 1mile) I can go the short route down busy main roads or loop around it and cycle down a nice country lane with a stream alongside it and very few cars, even at rush hour, just the odd tractor. I'll tend to add onto the 13 in nicer weather, depends how much time/desire I have. There is a funny road i can go down for a change sometimes, in the dry. Words cant describe how bumpy it is, but its great fun.