Start using OSRM

[jmealo]

OSRM routes 1000x faster than pgrouting. It is very lightweight and was able to handle 200 concurrent connections on modest hardware without breaking a sweat. It installs without issue and imports files quickly.

That being said, it's easier to use than pgrouting, with only one gotcha:

OSRM doesn't support costs/weights right now; but it does support speed and routing by road type and one-way/turn restrictions.

Until they support LUA-based weight/costs (planned feature), I think the following solution should work:

By assigning walkable road types a new psuedo-road type based on safety we can trick the routing engine into routing by safest route.

Each psuedo-road type can have a speed assigned to it. We'll make the safest ones have the lowest speed and prefer the lowest speed (as the "foot" routing profile already does).