Imagine how your community w o u l d be affected if tomorrow motor vehicle use were to double. This w o u l d impose many problems, or 'costs' to use the language of economics, including increased traffic and parking congestion, air and noise pol lut ion, and traffic accidents. Road maintenance and traffic law enforcement costs w o u l d also increase. There w o u l d be pressure to w i d e n roads and b u i l d more parking facilities, imposing financial and environmental costs. Over time, urban sprawl w o u l d probably increase and mobility for non-drivers decline.