Erf

An erf (literally meaning 'yard') is a Dutch term for a street where walking, cycling and recreation is formally prioritised over the flow of motor traffic. The plural is 'erven'. The official English translation of erf is 'recreation area'. 

Erven can be recognised by a distinctive blue sign, which visually demonstrates the priority of human activity over motor traffic.

Erven or 'recreation areas' are covered by Dutch traffic regulations - 

 

2.17 Roads across recreation areas

Article 44

Pedestrians may use the full width of roads that pass through a recreation area

Article 45

Drivers may not drive at more than a walking pace on roads that pass throguh a recreation area 

The concept of erven originates with the 1970s woonerven (literally, living yards), new-build housing that explicilty prioritised human activity. Erven are no longer explicitly residential and their principles can apply in different contexts. 

The closest UK equivalent to the erf is the home zone.