The entire model that each traveler needs their own personal vehicle to control where they want to go is ridiculous. The idea that a city should waste a significant fraction of its surface area in roads and parking lots is equally ridiculous. Worse still, the incredible inefficiency of transporting two tons of metal in order to move one or two people is laughable as a concept, not to mention spending $3 or more per gallon of gasoline in order to do it. And then, lo and behold, so many people are doing exactly this that nobody can move and you end up wasting gasoline moving along at a crawl through packed streets. Yet everyone seems to think that roads are a necessary, and perhaps beneficial, construction. In truth, roads are an evil, and efforts should be made to move away from the old model of transportation. The choice between fossil fuels and alternative fuels, while an easy choice (solar!) is beside the point. It’s rather like arguing whether to shoot the cat, or the dog. Alternative modes of transportation are the real issue.
Firstly, I don’t find any of these likely to become widespread in a short time. The road, the car, and the fuel industry have become too well-entrenched to be displaced quickly. However, that does not change the basic point that the reason why the road paradigm is the one used is because it produces a self-reinforcing cycle where car companies, oil companies, etc. make a killing. Roads are built, cars are needed. Cars are bought, fuel is needed. More cars are bought, jamming the roads, fuel is wasted, more roads are built. Because the roads are managed using taxpayer dollars, the insane expense of producing the infrastructure in sufficient degree to begin this cycle of addiction would prohibit the free market from anything of the kind. The government has huge legislative momentum behind perpetuating the use of roads and vehicles from the DMV to signs to highways to cops.
The bike. The best transportation system on the planet, it’s just that roads are poorly suited to them because there are so many cars. Bike-dedicated roads would have far greater capacity, move more people, and facilitate faster travel for everyone. Sure, it’s work, but think of it as exercise. Note that bike roads would work much differently than car-roads. You don’t need obsessive-compulsive lane management, or a number of other car-specific features. You wouldn’t need a license since it’s not dangerous or complicated.
The metro. Quite possibly the greatest mechanized transportation idea ever. It’s underground so it is completely out of the way, it costs almost nothing to ride and it travels quickly. Perfect for fast, cheap intra-city or inter-city long-distance travel. Why every sizable city doesn’t have one, I have no idea. They’re electric, they can be made quiet and comfortable with good wheels and air conditioning. Look to the French, everyone, they know what they’re doing.
The power pedestrian walk. This is a simple little gizmo, like you would find at a ski resort for the kiddies to practice with. It’s a simple lift/pull consisting of a single tilted panel that travels along a track. It goes, and you are invited to ride it. Optional but very sensible add-on; an upside-down-L-shaped bar for the rider to hold on to. In the space of two lanes of city street you could have a battery of perhaps ten of these. All the spaces on one track would travel at the same speed, so the capacity is only limited by how many people you can fit on it. You have it travel at maybe 10 mph, with fast lanes of 15 and express tracks going 20 or faster. They don’t have to ever stop moving. You pick one and you run up and catch it. For the faster ones, you’re going to have to transfer to them. Occasional conveyor belts, like those in airports, might help you match velocities. If you were to actually convert a street to be an alley of them, you would have to add apparatus to switch to more centralized, faster tracks. The effect of this is that, though you can’t get up to 50 miles per hour, you are never stuck in traffic. If they were as prevalent as roads you just walk over and hitch a ride along a path where a road might follow. You get off and then get on a different one when you want to turn.
The scooter. Carbon-frame scooters are light enough to carry in a backpack, folded up. You power it with, you guessed it, your leg. You could get an electric motor if you wanted to go faster independently. Or you could make them able to ride in power tracks so you just hang on and drop it in, and you’re off.
The zipline. Or, upping the ante, the aircar. Basically a means to travel over a city’s buildings instead of driving among them on a street. The pedestrian version is the zipline. You start from a tower, and ride a line down to a lower floor on a connecting tower. You somehow get to the appropriate floor of that tower; elevator, stairs, ropelift, whatever, and repeat. The technology is not complicated, and not expensive. No power required, not even electricity. It would be fast and efficient, and quite safe if the zip devices were well-made. The motorized version is the aircar, which does essentially the same thing but is a motor powered gondola. Motorized gondolas don’t need to concern themselves with stopping at each tower for passengers to climb on their own, they just go directly from tower to tower. They would probably follow fixed circuit paths in continuous chains from tower to tower instead of going back and forth between two towers.
The glider. This one is a little out there. Most people don’t know how to operate a glider, and if you don’t know how they’re pretty dangerous. But they are a quite feasible means of transportation if you allow a great deal of leeway in lanes. Not practical for close-in transportation, but if you need to cross a city or travel to a nearby city then it’s perfect.