|Location, Materials, Types|
Traffic calming devices should be placed so they do not appear unexpectedly in the street scene. Ample distance for prediction and reaction should be ensured allowing car drivers to reduce speed sufficiently or, if necessary, to stop.
A speed reducer and its surroundings must be designed so that there is a clear visual difference from the rest of the stretch.
It should be ensured perceive and observe the carriageway marking and road signs in due time, and if necessary pre-warnings must be provided.
For use of signs and road markings see “Manual for Signs and Markings”.
In this addendum some recommendations for use of materials are given. For further recommendations see “Standard Specifications for Road and Bridge Works”.
On Ghana Highway Authorities roads (or roads in Ghana (if this manual should be a national standard)) 7 different traffic calming devices are normally used.
In the following chapters, each of the 9 main types is briefly described. The application of the main types is shown in table 1.