From 1915 onwards the MTT had to compete against unregulated private buses, often preceding the trams on the same route to steal fares, which the MTT countered by opening their own motor bus routes from 1925. The South Australian government began regulating buses within the state in 1927, although some private operators argued that Section 92 of the Constitution of Australia, which deals with interstate matters, exempted them from following the regulation. By notionally marking each ticket as a fare from the pickup point to Murrayville, Victoria (but allowing passengers to board or alight sooner) companies avoided having to abide by the regulation for some time. The case was considered by the High Court, during the course of which Justice Isaac Isaacs offered a temporary compromise agreed to by both parties, but it appears that a final judgment was never delivered. Eventually, most of the affected bus operators sold their buses to the MTT or other operators who followed the routes described. Up until the end of World War I, most Adelaideans were dependent on public transport for daily journeys. The introduction of private automobiles decreased passenger numbers until petrol rationing during World War II led to a resurgence in patronage; patronage remained higher than before the war, until rationing was discontinued in 1951.