The PTV developer Routing API allows to calculate routes in a way that prefers turns to the passenger side. Truck drivers and delivery personal sometimes appreciate such a behavior because it can reduce waiting times and enhances safety.
To use this feature set the request parameter options[preferTurnsOnPassengerSide] to true.
The pictures below show the effect of the setting of preferTurnsOnPassengerSide.
![options[preferTurnsOnPassengerSide]=false](/sites/default/files/inline-images/preferTurnsOnPassengerSide_switchedOff_240x262.png)
options[preferTurnsOnPassengerSide]=false
![options[preferTurnsOnPassengerSide]=true](/sites/default/files/inline-images/preferTurnsOnPassengerSide_switchedOn_249x249.png)
options[preferTurnsOnPassengerSide]=true
The route on the left side was calculated with the default settings. It has driver side turns (left handed in Germany) together with passenger side turns (right handed in Germany) whereas the route on the right side consists exclusively of passenger side turns. Left hand traffic or right hand traffic is respected depending on the location of the considered crossing. Please note that the course of the route is based on a compromise between many properties like distance, travel time and others. Therefore driver side turns may occur even if the option preferTurnsOnPassengerSide is chosen.
Try it in the Turn Restrictions code sample.