The MapRoulette Blog

Adding directionality to stop signs in MapRoulette

Published: in Challenge by .

The highway=stop tag is the OSM representation for a stop sign like this:

A stop sign. Source: Wikipedia

They are often placed on the intersection node of two ways, if there is a stop sign in all directions (a four-way stop). There are plenty of situations where the an intersection only has a stop sign in certain directions. In that case, the stop sign node is often placed on the way at the approximate location ahead of the intersection where the stop sign is placed:

Stop signs placed before an intersection. Source: OSM wiki

In those cases, to make the tag unambiguous, it is recommended to add a direction tag to the node, to define in which direction the sign faces, relative to the directionality of the OSM way, as defined by the ordering of the nodes that make up the way: either forward or backward as illustrated here:

Detailed illustration of placement and tagging of directional stop sign tagging in OSM. Source: OSM Wiki.

However, the direction tags are often missing in OSM, making the tag ambiguous. When we recently asked for ideas for new MapRoulette Challenges on Twitter, fixing this was one of the suggestions!

It didn’t take long for the MapRoulette community to jump on this and create the Challenge for Matthew’s home province of Ontario, Canada. Thanks, Binnette!

These tasks should be fairly easy to solve, especially with the great instructions that go along with the Challenge. Can we fix all of them before the end of the year? Let’s get started!