[mkgmap-dev] Road speed through urban areas

Thu Jul 16 15:29:33 BST 2020

muralito at montevideo.com.uy writes:

> Be careful, if you drop the class for traffic_signals it brokes long
> distance routing, because (at least in South America) a lot of
> primarys and trunks have traffic_signals.
>
> I have been using the a map with a style that applies a -1 penalty for
> road_speed in case of traffic signals, and it works well in cities and
> in long distance routing, and it improves the estimated times.

What I meant is

  compute using a richer routing algorithm how long traversal will take

  compute what length to have a reduced class, or what length/reduction
  combos, to match the richer alogrithm

  make sure to do this in both directions

  demote for some class/distance, or perhaps the whole length for short
  segements between adjoining traffic_signals


essentially

  construct a network with road_class set so that routing on that
  network as garmin does, produces the same outcome as using a
  signals-aware routing algorithm

which I realize is a tall order