Once driverless car technology has sufficiently matured, there will be no need for buses, underground trains, or any other current public transport system. City authorities should be planning for driverless cars (including driverless "taxis" for those who do not own a car) instead of continuing to think about and invest in soon-to-be-obsolete modes of transportation.
In addition to the regularly mentioned benefits of driverless cars, such as reduction in road deaths, and freeing commuters to use travel time more productively, another very important advantage is significantly improved efficiency. Eventually cars will communicate their destination to a central computer, which will coordinate the journey with all other cars. The route and speed will then be determined so that cars traveling in different direction will cross junctions at different times, avoiding the necessity of stop lights and thereby allowing cars to travel at almost constant speed to their destination. Not only is this more time efficient, but avoiding the regular large expenditure of energy on accelerating from a stop will also make cars more energy efficient. Furthermore, the reduction in the need for acceleration means that cars will not require such large engines, and the almost elimination of car crashes means that weight can be greatly reduced by stripping safety features and heavy metal bodies, further improving efficiency. Taking more direct routes to destinations, rather than the circuitous routes often required when using public transportation, also improves efficiency. I am surprised that environmental campaigners are not all urging the rapid implementation of this technology. More efficient road use will also mean that existing road infrastructure can be used more efficiently, which may reduce the need for road expansion projects. City authorities should therefore not only avoid throwing more money into public transport methods whose days are numbered, but they should also be reconsidering road expansion investments. The money should instead be directed to driverless car research, and planning for this coming revolution.