As diesel vehicle emissions were classified as a major contributor to the brown haze, the Cape Metropolitan Administration treated this as a high priority. Despite the poor, cumbersome and outdated legislation available, the Cape Metropolitan Administration went ahead and initiated a control programme.

The diesel vehicle-testing programme commenced in February 1999. The existing Air Pollution Control staff embarked on a public relations exercise by setting up roadside tests and educating the public with respect to the legal requirements of the legislation. Warning notices were issued to offenders.

This was followed by the appointment of three diesel vehicle testing teams in December 1999. While continuing with the public relations exercise the new staff were extensively trained. Full implementation of the legislation with respect to the control of diesel vehicle emissions commenced in March 2000.

Suitable test sites are selected and vehicles are pulled off the road at random and subjected to the prescribed free acceleration test. Random testing of vehicles is done in order to be able to build up a statistical base of the condition of vehicles on the road and to judge the effectiveness of the programme over a period of time. In brief, the testing procedure entails the recording of the results of all vehicles tested. Owners of vehicles that fail the test are called upon by notice to repair and submit their vehicle for a re-test. Failure to comply with such notice will result in a prosecution.

The testing and re-testing results are captured on a data base programme specifically designed for this purpose. Re-testing is done presently at four MLC Traffic Departments and also by the diesel vehicle testing team.

Some 120 vehicles are tested during a week, weather permitting. Roadside testing is done with the assistance of the MLC Traffic Departments. However, investigations are being carried out to give the diesel vehicle testing teams full uniform status and authority to pull vehicles off. This will improve the efficiency of the programme and will relieve the traffic officers to concentrate on their own work.

It is clear from the intent of the legislation that the emphasis is in solving the air pollution problem and not to just prosecute the offenders.

Most owners of smoking vehicles have thus far been very conscious of the damage they cause to the environment and have hastened to take remedial action. Every smoking vehicle that is removed and repaired will contribute to a better environment. The City of Cape Town's testing programme cannot be seen as the only solution to improve air quality and ultimately needs to be supplemented with improved legislation and the reformulation of fuel.