IME commuting by motorbike through London over the past 10 years, most side roads aren't viable rat runs owing to one way loops that feed you back out onto the

IME commuting by motorbike through London over the past 10 years, most side roads aren't viable rat runs owing to one way loops that feed you back out onto the road you're trying to avoid. In north and east London, it's the canals and rivers that prevent a lot of rat-running. The Lee / Lea river and its reservoirs, all the way to the canals in Islington, down into Limehouse, cut out most alternative east-west routes - you need to cross those waterways by bridges, and only the bigger roads have bridges. And there are east-west canals too, that reduce the options north-south on the east side of the city.