Speed Management in Transition Zones Between High-Speed Rural and Low-Speed Urban Areas

Abstract

The study was performed on an existing national road in the Eastern Cape, South Africa. The R336 is a surfaced single carriageway two-lane two-way road starting at km 0.00 at the intersection with the R75. The study extends from the 16.75 km marker west of Kirkwood, up to the intersection with the R335 in Addo. The length of road assessed in the case study is 31.5 km and passes through 3 distinct urban areas namely Kirkwood, Sunland and Hermitage. The road is sign posted for 100 km/h in the rural areas and 60 km/h in the urban areas. Local residents reported severe accidents and complained of speeding in the urban areas. A literature study was conducted on how road authorities, engineers and planners have dealt with similar challenges. The case study’s safety concerns and mitigation measures then analyzed the best methods of reducing the speed approaching and within urban areas. Finally, recommendations were discussed as to the effectiveness of the case studies proposed mitigation measures as to how speeds can be reduced. The important conclusion was made that a motorist must be made aware that they are within an urban area. This was achieved by implementing the following in all three towns: • The urban cross section was adjusted. • The road surface width was reduced through the urban section. • A kerbed side walk on one or both sides of the road was used to create the sense of the urban area. • High visibility signage was used on all the transition zones. • Raised pedestrian crossings were kept to a minimum and placed in strategic locations.