• Because when the electric car is on the smart cart which has steel wheels, we have steel wheels on steel rail and the rolling resistance is reduced significantly—typically 50% of that of rubber tire on concrete roadway.
• At urban speeds aerodynamic drag is not a big factor, but there is no reason to think that overall SEGway aerodynamic drag would be much different than an automobile.
• In terms of the number of accelerations, SEGway will have far fewer, due to avoiding highway congestion, and both the smart cart and the electric car would have regenerative braking. Of all the energy requirements of motion, accelerations in urban driving is dominant and SEGway excels here relative to the automobile.
• Concerning mass: The electric car will not have a heavy battery pack because it doesn’t have to go long distances by itself, and it will not have an engine, cooling system, and fuel system. The smart cart will be quite light, only a platform with wheels, one or two small motors, and electronics console. So a smart cart with an electric car on it may weigh no more, or at least not much more, than a conventional car.
• There is nothing to say that the length of a trip via SEGway will vary from the automobile trip connecting the same origin and destination, on average.
• In terms of thermal efficiency, recent dynamometer tests by Argonne National Laboratory’s Center for Transportation Research show that in urban driving an electric car is substantially more gallon equivalent efficient than a gasoline fueled automobile. Certainly an electric car on a smart cart will be far superior because the energy does not have to go through two electrochemical conversions as when the electric car’s battery is charged and discharged.
• Empty backhauls: Unlike radial rail transit lines, SEGway will eventually be a network. When you look at urban trip pattern data you see that the inbound to the central city in the morning and the outbound in the evening trips are but a fraction of the total trips. The number of reverse commute trips is substantial and growing. Radial rail transit fails to capture many reverse commutes because once at the suburban station, the commuter has little choice of how to get to the work site. Suburb to suburb commutes are the largest portion of commute trips. However, until we are able to do some simulation, we cannot estimate the percent of smart cart miles that will be empty, but I expect with good smart cart management, it will be small, especially with a good pricing scheme and a few strategically located smart cart storage areas. Never-the-less, moving an empty light-weight smart cart around will not be energy intensive.

All the energy arguments made have been based on passenger movement. A similar set of energy efficiency arguments can be made for freight in containers shipped via SEGway.