The N1 links Johannesburg and Cape Town and the N9 links the N1 with Port Elizabeth and George. The previous at-grade intersection and the junctions with the access roads into Colesberg experienced very high accident rates.
Mariswe was appointed to alleviate these challenges and the project involved rehabilitation and widening of 31 km of the N9 and construction of a new grade separated access interchange at the intersection of the N9 and N1 national routes.
The new interchange enables free flow between these highways with two overpass bridges and nine access ramps. Safe access into Colesberg and crossing for local resident traffic and pedestrians over the N1 are included.
Public participation was key in the development of the interchange layout, including public meetings, discussions with affected businesses, a noise study and socio-economic study of the impact of the proposed works on the local community.