Let’s Fix Duplicated Highways in South Africa Together!

Communities South Africa
1

Hello everyone,

I Hope you’re all doing great! Hajar from TomTom here. I wanted to reach out and invite you to a new MapRoulette challenge to help clean up duplicated highways in South Africa.

Your local knowledge and mapping skills make a huge difference, and this is a great chance to improve OSM together!
:point_right: Join the challenge here: MapRoulette

Every edit helps make the map more accurate and useful for everyone. Let’s fix these together—happy mapping!

2

What QA are you planning to have in place to monitor Maproulette contributions as they come in?

The reason why I mention this especially here is that there have been past issues with eager and well meaning contributors not always understanding how road mapping in OSM works, and the local community is sometimes fairly thinly spread. A previous issue from 2021 was this one, mostly resolved here. That particular issue wasn’t spotted for a while which meant that the resolution was much harder - and may actually have caused some of the duplicate highways that you’re fixing here!

Monitoring for rogue semicolons in the lists here and here would be a great start, and changes in major city route distance would spot breakage (of course - you may very well already be doing this).

3

Hi Andy,

Thanks for your suggestions and for sharing those historical references to errors in the map. You’re absolutely right—fixing one issue can sometimes introduce new ones, and many data problems are interconnected, making them tricky to resolve.

At TomTom, we put a lot of focus on the road network, and right now, we’re keeping an eye on:

  • Incorrect modeling, overshoots, and redundant short road segments
  • Missing nodes in junctions
  • Road network spikes that affect user experience
  • Missing or incorrect roundabout tags and exit/entrance connections

We’re continuously improving our quality checks to catch and fix these issues more effectively.

Another key aspect is the quality of edits themselves. For TomTom challenges, we regularly review and sample edits to ensure they follow OSM guidelines, proper capturing methods, and verified sources. If any issues slip through, we correct them and provide feedback to mappers to help avoid similar mistakes in the future.

I hope this answers your questions! If you have any thoughts on how we can work together to improve OSM, I’d love to hear them. South Africa is a key focus for us, and we’re always open to ideas from the community.

Best,
Hajar

1 Like