Mapping turn restrictions allows our Directions API to find the best route to your destination. Cities restrict turns to optimize traffic flow along certain corridors or for safety purposes, and they are a critical part of the underlying data in the map for navigation. Currently, there are over 520,000 turn restrictions in the OpenStreetMap database added by mappers around the world.
If you have questions or suggestions for our guide on mapping turn restrictions, find me on Twitter. And if you are attending State of the Map US join Shiv for the Tagging and mapping for routing and navigation workshop on Monday, July 25 at 2:30pm!