De Vries, J.C.; Pretorius, P.; Oosthuizen, P.G.W.; Southern African Transport Conference (20th : 2001 : Pretoria, South Africa)
(SATC, 2001-07)
Paper presented at the 20th Annual South African Transport Conference 16 - 20 July 2001 "Meeting the transport challenges in Southern Africa", CSIR International Convention Centre, Pretoria, South Africa.