Not a good idea. Automated trains are proven safe reliable transportation. Automated cars are not. The capacity of even automated cars will be far less than that of the rail. It would be a big waste of money. Plus ramps would have to be built to get the cars off and on the guideway. The merging onto it would further reduce capacity. The result would be a huge waste of money and there is a good chance it would not even work. A much better idea is to complete the rail then, when they finally become practical (which could be several decades), use shared automated vehicles (cars, vans, buses) to get people to and from the rail.