openplans/OpenTripPlanner — Issue #538: Mode Specific Turn Restrictions
Author: grant-humphries
Created: 2011-10-13 00:56:02+00:00
State: open

In OpenStreetMap one can specify that turn restrictions apply only to particular modes of travel. Turn restrictions are relations in OSM and are tagged with the following:

type=restriction
restriction=* (i.e. no_left_turn)

When there are exceptions to which kinds of vehicles the turn applies to they also have the following tag:

except=*

the main four values for this tag are: bicycle, motorcar, psv (public service vehicle), and hgv (heavy goods vehicle) although OSM users can always introduce new values.

We need OTP to be able to implement these mode specific turn restrictions because there are several key intersections in Portland where bikes are allowed to make turns that cars are not.