The Transit Dilemma

When a person looks at their transportation needs, they ask the question, "can I get a set of solutions that will give me a good trip along all, or almost all the paths I want to travel?"

It turns out to be very hard for transit that runs on lines to solve this problem, because to work, the transit has to have stations that are quite close to both ends of the journey. Furthermore, it has to provide a fairly direct route between the two points, or the trip takes far too long for anybody with other means. Third, it has to have fast and frequent service between the points, and it has to have such service at all hours of the day.

PRT dreams of solving some of these problems with point to point service. PRT uses offline stations, so your small vehicle goes directly from station to station, leaves when you want, and runs all day. That's a major jump ahead of traditional shared transit.

But even if you cover half of a city, and it's the densest contiguous half, with the most trips within it, most people are still going to have some trips to or from that other half.

If you can make that fraction of trips very, very tiny, then people might decide that they can forgo those trips, or even pay exorbitant taxi rates for just those trips. But as soon as the volume of the trips gets above a fairly low level, the traveler is going to make the leap to saying "I need a car."

Once they say they need a car, much of the battle is lost. Because now that they have a car, the incremental cost of using the car is low. Indeed, much of the cost of the car is fixed, so many people feel taking transit saves only the gasoline, parking and a little bit of wear. As a result, the rider only takes transit on very specific trips where it can beat the car, because of its private right-of-way at rush hour, or because of the hassles and cost of parking.

If this can happen on the daily commute, as it often does, that's enough to sustain the transit line. But ridership falls away outside the commute.

The only city in the USA to seriously reduce car ownership is New York. (Where car ownership is still over 20%.) Many attribute that to New York's abundant transit, and while that plays a role, I think the real reason for New York's car-free success is the abundant taxicab. Taxi trips in New York are mostly short, and thus cheap, and in most places cabs can be hailed. Taxis provide the point to point travel that fills in all the gaps in transit, and this allows people to decide not to have a car. Even wealthy people, who in many cases never ride the subway, but still don't own a car.

With door to door service, Taxis can be taken shopping, or with luggage, which is hard on transit. They make the difference.

It is for this reason that I think only robocars or whistlecars can replace the human driven car in most U.S. cities.

Making cars more incremental

There are proposals to take steps to make people view cars trips as having a per-mile cost. Some are easy to do, some require considerable market interference by the government.

One simple proposal is to require that insurance and car registrations be priced by the mile. Scheduled car maintenance is already usually priced by the mile, but some car vendors include it in the price of a car - this could be forbidden.

To get more draconian, car leases could be forced to be priced only by the mile -- today they usually involve a startup payment and a flat rate that includes an average number of miles, after which they are priced by the mile. But the reality is that car depreciation does take place over time as well as over the miles, so this is a major interference in market pricing.

Even purchased cars could come with a depreciation meter on the dashboard, which is an odometer for cost, based on blue-book data.

Free parking could be eliminated or reduced.

While a gas tax is the simplest way to make the cost of driving more incremental -- and many feel that being per gallon is actually more conducive to social goals than per mile -- there are also calls for more exact per-mile pricing. These are coming from "congestion pricing" systems which charge extra if your car goes into special designated areas. This can be done with licence plate cameras, RFID transponders or GPS loggers in the cars. All of these have serious privacy problems, with the GPS loggers being the worst.