For a courtesy crossing to be effective, drivers need to: know that they may need to stop; see and understand where they should stop and (importantly) be travelling at a speed that allows them to stop. This means that they need to be travelling at or below about 20mph.
These speeds are achieved by either legally enforced speed limits and/or traffic calming techniques. Traffic calming has been lawful in the UK for some twenty years notably by various types of road hump. But there are many other more acceptable methods that reduce speed while enhancing the quality of a place with landscape, trees and sculpture.
The full range of lawful traffic calming measures, other than road humps, is set out in the UK national Traffic Calming Regulations, 1999.
The inclusion of courtesy crossings as part of traffic calming is accepted in the Department for Transport’s Local Transport Note 1/07 Traffic Calming
DfT research found that drivers were more likely to stop for pedestrian where the road was either one way or had a central refuge (paragraph 2.7.8 and 9)
Speeds at or below 20mph were found to reduce child accidents by 79% (para 2.7.11).