Us Brits get very excited about public rights of way - routes, often over private land, that the public has a right to use, usually because the locals have been doing so for as far back as anyone can remember. These routes are classified into footpaths and bridleways (and then public highways). Horses and bicycles are permitted along bridleways, but not footpaths. Arguably you don't need a map to distinguish bridleways and footpaths because people will tell you when you get it wrong...

Physically, a bridleway can be anything between a tarmac road (if, for example, it follows the route of someone's driveway) to a path that you would have trouble walking along, let alone getting a horse through.

Paul