1.2.1 Reduced energy consumption
The coupling of RUFs will reduce the energy consumption significantly, because the air resistance is almost eliminated for the RUFs in the middle of a train.
An electric vehicle is a little more energy efficient (counted from the primary source) than a normal car. This comparison favours the electric vehicle, if excess heat from the power plants is used as district heating. If the batteries are charged during the night, the power is cheap and the EV drives more economically than an ICE car.
The important difference appears when a RUF enters the rail and form a train together with other RUFs.
The rolling resistance is reduced, because the rail wheels can be quite smooth, since the RUF has a rail brake for emergency braking.
The air resistance can (according to a calculation from the Technical University of Denmark) be reduced significantly per vehicle in a RUF train. Since the rail is meant to substitute the highway driving, the savings occur exactly where the normal car uses most energy (individual driving at high speed). Another critical situation for the normal car is stop-and-go driving in the city traffic. Since the RUF is electric, it does not run idle and it is furthermore possible to regain part of the kinetic energy using regenerative braking.
Heating and air-conditioning is a problem in electric cars. It is not a problem as long as the RUF is using the rail power, because all the power needed is available without using the batteries.
The RUF is controlled by the system while on the rail, so it is possible to use the most energy efficient driving pattern.
No cold start emissions.
No driving light is needed on the rail.
Using electricity means that any improvement in production technologies will have an immediate effect.
The dependence on oil will be reduced.
1.2.2 High capacity
The capacity of one rail is much higher than the capacity of one highway lane.
In a typical situation where the rail is used by 50% RUFs and 50% MAXI-RUFs, the capacity will be 20,000 seated pass/hour/direction. It is based upon 1.2 pass/RUF and 7.5 pass/MAXI-RUF. This is better than for a typical Light Rail system as the French VAL system (1 minute interval and 2 cars per train). VAL has a capacity of 17,000 seated and standing pass/h/dir.
It is also significantly higher than the capacity of an Automated Highway lane where cars are creating platoons with 1.5 m distance between cars.
A RUF-train with closely coupled RUFs has a30% higher capacity than a car-platoon with 1.5 m between cars.
RUF-trains can be longer than platoons because the control systems making the platoons tend to become chaotic when the platoon gets too long. A train of closely coupled RUFs can be any length needed.
The safety distance between platoons is defined by the braking performance of the worst car in the platoon. In a RUF-train there is a very powerful rail-brake. Furthermore, since all RUFs in a train are closely coupled (mechanically) one weak RUF will not prevent the train from safe and effective braking.
Short safety distances means high capacity because the trains can follow each other closely. Platoons cannot drive closer than the safety distance for the worst car. Normal trains cannot drive close either, because the brakes are poor (steel against steel means low friction and low braking power). A train is also limited because it contains standing passengers. If it was able to brake fast, the standing passengers would be hurt.
Another important factor determining the capacity is the switch. In a system with a moving rail, the distance between trains has to be long in order to be able to stop the train if the rail didn't move.
The RUF switch is without moving rail, so RUFs can switch to different directions even if they are driving with a short separation (10 m).