DennisOSRM/Project-OSRM — Issue #167: model of turn restrictions?
Author: emiltin
Created: 2012-03-06 10:36:29+00:00
State: open

i understand turn restrictions are not that far away, and what's essentially missing is just a good model. copenhagen university are intersted in helping out and provide parameters based on their research and data, but we need a better understanding of what such a model should consist of.

to get things started -
i imagine that there are 3 types of turns: normal turns, sharp turns, and u-turns, and that a penalty value is needed for each type of turn. so maybe something like:

```
side type angle range penalty
--------------------------------------------
left turn 20..160 0.1
left sharp turn 140..160 0.3
left u-turn 160..180 0.6
right turn -20..-160 0.1
right sharp turn -140..-160 0.3
right u-turn -160..--180 0.6
````

an alternative could be generalize this into a single 'continuous' formula that takes the angle as input and returns a penalty.

thoughs?