When my employer moved me to a different site a few months back I spent a couple of Sundays before the move riding routes to the new site, and planning a route based on what traffic at peak hours would be like.

The resultant route I normally ride is about 15 miles, takes me along a mixture of gravel paths, main roads, and country lanes, and takes about 50 minutes to an hour.

A straight route on main roads is 12 miles, taking about 40 minutes - I've ridden this route occasionally when the lanes have been icy, and there's no pleasure in it at all. I'm much happier doing the extra miles on quieter roads with the scenery that goes with them.