MapRoulette challenges in Singapore

Hi all,

This is Andrew from Apple’s Maps team. A while ago we started working on OSM data issues in Singapore ( and we recently used our Atlas data analysis tool ( to look at a few types of potential issues, such as building-road intersections, crossing roads that aren’t connected, roundabouts that are modeled or tagged wrong, and “sink islands” which are places where it’s impossible to navigate into or out of, usually due to incorrect one ways or missing roads.

I’ve posted the results of those checks on MapRoulette, a tool that lets you go through potential issues one by one and either correct them or indicate they are not a problem. I wanted to let you know they are available in case others wanted to try fixing some of them — I also plan to go through some of them myself.

In MapRoulette you can either pick a random task to fix or click on a specific one. If you want to do tasks around a certain location, such as somewhere you are familiar with, you can click “more options” then “load tasks by proximity.”

The checks are:

Please let me know if you have any questions or feedback.

Thank you,


Hi all, I’ve updated the challenges and added a few new ones. Let me know what you think!

Singapore Invalid Turn Restrictions:
Singapore Overlapping Lines:
Singapore Sink Islands & Impossible Routing:
Singapore Malformed Roundabouts:


Hi all, I updated the challenges with new OSM data and also put them all in a project, so you can just go there for the latest:

They include things like overly sharp road angles, roads that cross but aren’t connected, roads that aren’t connected to anything, overlapping roads, turn restrictions, roads that are close but not connected to others, and other similar issues. I plan to work on some of them myself too. And thanks to EditConscript who already finished a few!


I updated the Singapore challenges on MapRoulette, and added new ones about lines that cross over the coastline. You can see them all here:

Thank you for mapping before, the previous crossing road, sharp angle and overlapping ways checks were finished!

Hi Andrew,

I am a new user for OSM. I just check out maproulette and this seems fun.
Will try it out for edits near my area first.

Hi all, I updated the MapRoulette challenges again with new OSM data:

The updated challenges are overlapping roads, crossing roads, sharp angle roads, floating and disconnected roads and connectivity, which is roads that are near others but not connected. Please let me know if you have any questions or feedback. Thanks!