London Wiki

From the longer Wikipedia page [1]

The term red route has been separately adopted for two entirely different highway purposes within the United Kingdom.

In London, Leeds and the county of West Midlands in the United Kingdom, red routes are major roads on which vehicles are not permitted to stop, first introduced in north and east London in 1991. The prohibition extends to stopping for loading or unloading, and to boarding or alighting from a vehicle (except for licensed taxis and the holders of blue badges). Red routes are mainly used on major bus and commuting routes.

Red routes are marked with red lines at the sides of the road. Double red lines mean that the regulations apply at all times and on all days. Single red lines means that the prohibition applies during times displayed on nearby signs or at the entry to the zone. Red route clearways are signed but there are no lines on the road. Stopping is only permitted in lay-bys (red lines are only marked at junctions).

The 580 km of red routes in London are policed by "Red Route Patrols" and managed by London Streets, an arm of Transport for London.