R21 highway, Olifantsfontein SITE NUMBER : BB127-11 DESCRIPTION : R21 highway - travelling from Kempton Park & ORT Airport towards Pretoria. Between Olifantsfontein and Nelmapius off-ramps. SIZE: 4.5m x 18m TRAFFIC : 165 000 /day GPS CO-ORDINATES : -25.923903, 28.262312