Route GuidesRoutes City GuidesCities Map Log in

Avoid A/B roads?

21 Sep 2017
by Winfried
in forum
Find a better bike route. Try our map & route-planner »

Become a supporter


I recently road in the UK by following routes suggested by  I knew A roads were to be avoided at all cost, but even B roads were crazy to ride on with drivers passing very close and very fast :-/

Unless I missed it, it doesn't look like the router lets users choose to avoid riding on A/B roads. If it so, I suggest adding this feature.



Fri 22 Sep 2017, 13:35

Quick answer is – no, I’m afraid the routing algorithm used by (Contraction Hierarchies, via the OSRM engine) doesn’t really permit route options like that. It would require a whole new routing graph to be generated for each combination of options, which means a lot more servers and memory (and hence expense). Sorry!

Looking at A and B roads in particular, the challenge is that some A roads look like this (A14 at Kettering) while others look like this (A832 in the Highlands). The same is true of B roads – some are lovely quiet country lanes, others are crazily busy rat-runs.

To take account of this, uses real traffic data rather than just the road class. A road with 100 cars a day is probably pleasant to cycle, whereas one with 20,000 certainly isn’t. So if you have any examples where has chosen a busy road and a better, quieter alternative is available, I’d love to know.

Unfortunately, though, much of this is just how cycling is in the UK – especially in hilly areas. There’s often only one road in each valley, and it’s very busy; if you want to avoid traffic, you have to take a much hillier route. Difficult decision!

Wed 27 Sep 2017, 09:05

Thanks much for the infos.