turn penalties

[emiltin]

this commit implements a simple turn penalty formula that squares the turn angle (where straight ahead is 0, uturn is 180), scales it and multiplies it with the "turnPenalty" speedprofile setting. in addition you can set "turnBias" to make left turns more expensive than right turns (or the other way around). 1 (or leaving it out) means no bias.

this seems to work quite well. it really helps to smooth out routes a bit - you avoid overly wriggly routes with a minimal increase in length.

"turnPenalty" or "turnBias" can be left out in the speedprofile in case you don't want to incur turn penalties.

[DennisOSRM]

Cool, will have a look tomorrow.

[emiltin]

the turnPenalty setting is adjusted to be the distance that will be added for a 90 degree turn with bias 1.
suggested settings (for bikes, left side driving) are included in speedprofiles/bicycle.ini:

turnPenalty = 50
turnBias = 1.4

[emiltin]

if you're routing across several countries, some might have left side driving, and others right side. i suppose the bias would have to be left out in this case. otherwise you would need some way of setting the bias for each way depending on country.

[emiltin]

#167

[DennisOSRM]

Will be fixed or at least fixable with the implementation of issue #1

[emiltin]

looking forward to trying it out

[DennisOSRM]

Will be fixed with implementation of issue #1. Therefore closing as duplicate.