Individual Mass Transit
No fantasy city would really be complete without some form of mass transit system. The advantages of mass transit just can not be ignored. No looking for parking spaces. No traffic jams. Little or no accidents. Cheaper and more fuel efficient. No traffic police. Many delivery jobs could be eliminated making life simpler and safer. No need to look at a map. No air pollution.
Only some of these ideas are theoretical. Most are more tried and true. For example, the idea that the city won't feel crowded is a tried and true. Where I'm living right now, the local population density is similar, yet it doesn't feel crowded at all. Why? Because there's very few cars, which means very few roads and very few parking areas. It's like living in a park.
Where I'm living right now, they have a mass transit system, only it's a far less expensive, but it makes a suitable alternative.
The system they use here works this way. They have a lot of vans, each capable of carrying up to about 14 passengers. They all follow specific routes, and don't stop unless someone shows a simple hand gesture, or if someone in the van requests them to stop.
Since they are so much smaller than buses, there are a lot more of them on each route. This means that a person doesn't need to wait long. People traveling short distances, need wait only a few seconds, while people traveling across town might wait 5 minutes or so for a van that follows exactly the right route. It's a very comfortable system, and it works quite well. I highly recommend it. The cost to ride is 20 cents, which is less than turning the key to start a car.
With our new society though, our larger cities will likely use a different form of mass transit. Not that they need to, but rather because people will probably want it. For large cities, it is a good investment.
There are many ways of moving large numbers of people. Each way has it's advantages and disadvantages. Each is useful in one way or another, and no system works best for everything. When it comes to commuting to work it is obvious that individual cars is best. Not the polluting, expensive, inefficient cars that we have on our roads today. Even buses work better than those. We need fuel efficient single passenger (and multiple passenger) cars. Cars that are computer controlled, and travel on indoor railways. The combination of indoor railways, intelligent design, and computer control could almost virtually eliminate accidents.
Computer control, means that the cars will automatically make best use of all available railways, thereby completely eliminating traffic jams. It's not like we got a few multi-lane freeways running through the city, we got two lane freeways on every block, and the computer can make full use of all of them. Sort of like having several 100 lane freeways running through the city. There won't be any traffic jams. Ever!
They're all indoor, further isolating the already quiet electric car noise, from the pedestrians in the park areas. Women can feel completely safe, as they are individual cars. No chance of getting raped or mugged in the cars or in the station. No need to walk to the bus stop or train station, they go right to your building. They actually go inside your building. Multi-passenger cars are available for families.
As for reducing greenhouse gas emissions, with all electric personal mass transit, and potentially everything else could be electric, leaving the only potential for green house gas emissions being what is chosen to produce the electricity. Even so, the city would be far more efficient, using far less energy than other cities.
Of course, this is a city which would only come to life in a society like Conceivia. Perhaps 100 years from now, current societies might evolve that far, if they don't kill us all in nuclear war.