Let's map missing turn restrictions in Canada

Posted by manoharuss on 20 July 2016 in English (English)

Turn restrictions are the last missing piece in the puzzle to make OpenStreetMap ready for accurate routing. With Mapillary street photographs and their traffic sign recognition, it is easier than ever to start mapping missing restrictions onto the map.

At the data team in Mapbox, we have been experimenting with creating mapping tools to simplify such efforts and after adding over 1,200 turn restrictions in 30 US cities, we are ready to start mapping in Canada with the help of the local mapping community! Our team will focus on the following 5 cities: Ottawa, Toronto, Montréal, Vancouver and Calgary


How to contribute


If its your first time mapping turn restrictions, read the guide to mapping turn restrictions using Mapillary to understand different scenarios and special cases.

Use the OSM navigation map to compare traffic signages from Mapillary and the map data for potential restrictions to add. You can also review the photograph and mark the restriction as valid or invalid.

Check out our project tracker for all the details and collaborating your efforts with the Mapbox data team.

Marking a detected no left into a oneway as redundant restriction on the OSM navigation map


More Mapillary = More detected signages that can be mapped. Check the Mapillary coverage in your city and fill in the gaps! Calgary currently has the poorest coverage amongst the 5 cities. This tutorial will help you can get started with Mapillary.

Measuring progress

We estimate it to take 1 full week to review all the detected turn restrictions in the 5 selected cities with just our team. But could finish it off sooner and add more restrictions with a wider participation. These are the current number of restrictions present that were queried using Overpass:

Canada: 12,700

  • Ottawa: 447

  • Toronto: 1,129

  • Montréal: 372

  • Vancouver: 441

  • Calgary: 64

The road ahead!

It would be amazing to have the Canadian Mapping Community to help us out in making the map of Canada more navigable and enhanced. We would love to hear your ideas and thoughts on how to make our existing workflow better. Interested folks can contribute to the Mapillary coverage in Canada which would certainly help us add quality data onto the map! Let’s all join hands in making OpenStreetMap the best!

Comment from Skippern on 21 July 2016 at 00:33

Tried to edit some street signs in Mapillary, and it seems like the OCR recognition and the sign edit is down temporarily, probably to rework the API and the database. Hope it comes up again soon (it have been down at least since April)

Comment from manings on 21 July 2016 at 09:17

@Skippern, I pinged the Mapillary team about your issue, see:

Do comment on the ticket if you continue to notice the issue. Thanks!

Comment from manoharuss on 22 July 2016 at 05:28

@skippern Mapillary just launched a new website yesterday. In regards to your concern, we observed an increase in number of road signage overlay in Navigation map by a lot yesterday.

Make sure to zoom in above 14 though to see these in the Navigation map, there is a request to allow display of detected signage overlay at much lesser zoom levels.

screenshot 2016-07-22 10 47 39 Not sure why. Hoping the Canadian mapillary contributors have something to do with this.

This means we have a lot of turn restrictions to map. According to this Overpass polybox query, the turn restrictions in Ottawa increased from 450 to 476 yesterday, which is awesome.

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