Don't know if this has been mentioned, but in case anyone is interested in this 'bikedata map' on cyclestreets:
https://bikedata.cyclestreets.net/#17/51.51122/-0.10508/opencyclemapOn the map style choice there are some historic map options e.g. First series OS 1:25000 1937-61 (some zoom level dependent), OS 1 inch 1955-61
Strava heatmap overlays
Collision data
Vehicle counts
Planning permissions
etc
