The study examines factors affecting the determination of speed limits for each class of road and considers by what means speed limits should be enforced. Philosophical problems, caused by the search for a common unit to evaluate the diverse consequences of changing present speed limits, are discussed. Relationships are explored between speed and danger, fuel consumption and air pollution, and noise. It is demonstrated that lower speed limits would weaken the case for new roads, permit roads that might be desirable to be built to more modest and less intrusive designs, and reduce maintenance costs. Recent increases in speed limits are utilised to suggest how travel patterns might change if speeds were reduced. Consideration is given to speed limit levels on motorways, other main rural roads, and roads in towns. Methods of enforcing speed limits are examined, and the politics of speed reduction are considered. Appendices are given containing detailed supporting arguments and calculations.
Abstract