If you use the iD editor you are possibly familiar with the MapBox locator layer which appears as one zooms out. There’s a fairly recent post from MapBox about this layer (on Medium).
This transparent layer is also used in other MapBox products and therein lies a problem.
I noticed a tweet complaining about the position of a motorway (or planned motorway) on a local active travel portal for Newport, South Wales. Someone pointed out that the map is credited to OpenStreetMap & MapBox, which caused someone else to say:
“Well now I know why I don’t rely on open source maps …. it’s frustrating as ‘that’ m4 has been the source of plenty of political debate and has been widely regarded as the only way to solve Newport’s congestion”
It took me a while to work out what had happened (with help from russss & trigpoint). There have long been highly controversial proposals for a new route for the M4 motorway around Newport because the current route is prone to congestion. At some stage in Summer 2018 someone mapped one of the proposed routes on OSM (as highway=construction). This incorrect tag was not changed to proposed for several months, but the ways were then removed from OSM when the proposals were dropped in 2019.
Incidentally, it’s not the first tweet complaining about OSM from a cycle campaigner this week.
