To get an indication of road adoption status:
Go to your desired road on the map.
Click the "map layers" button on the right-hand side.
Select the “highways maintenance” layer to display it. In general, adopted roads are green and unadopted in dark red.
Hover over a road to check its status, see who maintains it and confirm the name of the road.
You can also follow these steps to identify public rights of way by selecting the "Public Rights of Way" layer instead.
TIP: You can also view most roads in street view mode and check registers for surrounding properties to see who has rights of way or responsibility, find out how here.
TIP: Creating a site plan? Road names will only appear on Ordnance Survey maps, not on the aerial map. To help explain the lay of the land to clients try creating an Interactive Walkthrough and adding a comment.