In most cities, driving -- although it comes with its own frustrations -- is a completely viable way to commute. Sitting in traffic and maintaining a car are negatives, but being able to travel whenever you need to and going directly to your destination are huge pluses. So public transport must be competitive with driving. It must win in convenience or value or both. In some places like Manhattan, driving is so painful that public transport usually wins out. But, in many cities driving is more convenient and sometimes even cheaper. Of course, comparing cost is not easy since roads and buses and rail are usually all funded by an amount of general tax revenue.