Crime is obstructing urban planners' efforts to wean South Africans from their motor cars back to using mass public transport. This in turn leads to traffic congestion and urban sprawl as motorised transport makes living on the urban peripheries, where property prices also tend to be cheaper, more viable. Analysts agree that a primary aim of planning law is to contribute to the citizenry's safety and security, but a major contributor to traffic congestion is the need parents feel nowadays to ferry their children to and from school due to its being too unsafe for them to walk or cycle. The dangers of traveling by train are highlighted by class-action cases brought against Metrorail for failing to provide adequate security on its lines. There is a range of South African land-use legislation which calls for urban compaction. The Integrated Development Plan (IDP) is the instrument municipal planners should be using to give effect