The car is the major mode of transportation in the modern society. As a consequence, many large cities are suffering from severe congestion and pollution caused by the car. Public transportation systems are not able to attract car drivers because of the inflexible nature of the train systems. The RUF system is a system which combines the flexibility of a car with the advantages of a train.
Car drivers who choose the RUF instead of the car will be able to drive directly from door to door just as the car. Instead of using the highway, they use a triangular monorail placed 4 m above the middle of the road (or in a separate lane). The RUFs on the rail are coupled close together while "riding" on the rail. This coupling principle will increase the capacity of the rail and decrease the air resistance of the RUFs. The increased capacity will reduce congestion and the reduced air resistance will reduce all emissions from the system.
Most modern cities are too widespread to be serviced by an ordinary train system. It is not acceptable to walk more than 300 m to a station, and waiting times must be very low. It is unacceptable to have to transfer between bus and train. Consequently, people use the car instead of the train. The dual-mode RUF can go directly from door to door and start whenever the driver is ready. The rail system enables safe driving at high speed with low energy consumption and high capacity. The RUF can leave the rail at junctions along the rail (5-20 km apart) and continue as an electric car. Switching from road to rail and from rail to road is done at 30 km/h. Rail driving is fully automatic.
The rail network can have stations (off-line) where passengers can enter RUFs or MAXI-RUFs. Every passenger is seated with the same comfort as a car driver. Every unit (RUF or MAXI-RUF) drives non-stop between stations.
The passenger can completely relax, since the RUF doesn't stop until the destination station. The RUF-train will slow down to 30 km/h while passing the intermediate stations, but it will not stop before the passenger has reached his destination. The departures are very frequent. Waiting times are almost eliminated. The system operates 24 hours a day. The use of the system is controlled by a personal smart card.
Normal electric cars have a severe range problem. Large batteries are needed in order to obtain a sufficient range. Large batteries are heavy, costly and take a long time to recharge. The RUF takes current from the triangular rail, so it is able to recharge while driving on the rail. When leaving the rail, the RUF is powered by small batteries. In a large city, all destinations will be within 10 km from a rail junction, so a range of 50 km is quite sufficient. Small batteries means low rolling resistance, low braking losses, low initial cost, low replacement cost (typically every 2-3 years with present battery technology) compared with the batteries of normal electric cars.
RUF vehicles "ride" on top of an "ultra light" triangular monorail. Since the RUFs are much lighter than normal elevated trains (300 kg/m for RUF vs. 1000 kg/m for a typical train) the rail structure can be very slender. The rail sections can be mass produced at a factory and moved to the construction site via the finished rail.
Compared to alternative methods to increase traffic capacity in order to reduce congestion, the cost of implementing a RUF system should be very low. No leveling of the ground is required and only very little land is needed for the columns.
The typical user will start at his residence (where the RUF has been recharged during the night) and drive a few kilometers to the nearest rail. Before entering the rail, he will tell the RUF computer where he wants to leave the system. He will enter the rail immidiately and couple together with other RUFs to form a train while driving at low speed. After a very short time, the train speeds up to 100 km/h and travels towards the destination. If it is a long distance rail, there will typically be 20 km between junctions, where all RUFs slow down to 30 km/h before entering the switching area. If it is a short distance rail, the distance will typically be 5 km. In the switching area, the RUF is automatically guided in the desired direction (to another rail or transfer to road driving). The driver can relax since the system controls the driving until the point where he manually takes over again for the final leg of the trip. If the RUF is owned by the driver, it will be parked as an ordinary car or automatically via the rail. If the RUF is a public vehicle, the driver can leave the RUF at an off-line station and walk the rest of the distance. This will be most attractive if the destination is in a dense area of the town. It will also be cheaper, since the public RUF can be used by other passengers during the day (via the personal smart card). In the evening, the RUF (private or public) can be used for all kinds of short errands. This is a big advantage compared with using a normal car for short trips. Cold starts are very harmful for the environment.
The development of ground transportation systems seems to have been divided into two opposing camps. Car developers have concentrated upon building better cars, while train developers have been focussing on improving the trains. Nobody seems to have put energy into the development of systems combining car qualities with train qualities. For me (Palle R. Jensen) as an independent professional inventor, it became obvious that the answer to the problems of traffic in big cities is a dual-mode system like RUF. Since 1988, I have used income from other inventions to finance the development of the RUF concept. It has been developed in Denmark where we have very few traffic problems compared with other countries, so funding has been a problem. A Danish consortium, RUF International, has been created in order to develop and standardize the RUF system.
In a city where congestion is a major problem and where the density is too low to be served by a train system, RUF rails can be placed along major arteries in the city as an elevated rail 4 m above ground, or at ground level but screened from the surroundings by a fence. Only few rails are needed, because the dual-mode RUF can drive 50 km along the normal roads. A two-way rail in the middle of a 4-lane highway will more than double the capacity of the highway. If many car owners convert to RUF, congestion will be significantly reduced.
In a city with major congestion problems, the cheapest solution will be to implement a RUF system. The users will be willing to pay a relatively high price because they get:
- a congestion free drive
- short and predictable travel time
- no transfer between transportation modes
- high class comfort
- privacy
- no parking problems (if the RUF is public)
- a good conscience because they create very little pollution
As the construction cost is relatively low (mass produced ultra-light rail elements, very little land area required, and easy mounting), it will be a profitable business for private RUF rail operating companies. Furthermore, a percentage of the users will finance their vehicles themselves. The operating company will build the rail system and a number of public RUFs as a start. As a large customer (>10,000 RUFs), the operating company will be able to keep the initial cost of the RUFs down and to ensure that the system will be of high quality and have a long lifetime. Several manufacturers will compete to deliver the RUF vehicles. The rail can be used by both dual-mode RUFs and the larger MAXI-RUFs (10 passengers). The operating company can offer mass-transit via the rail if a large portion of the RUFs are MAXI-RUFs driving automatically between off-line stations. The passengers will like the system because it will offer:
- very high frequency
- seats for everybody
- non stop between stations
- privacy or company by choice
- easy wheelchair access
- smart card tickets
- safe platforms
- speedy loading and unloading
All RUFs have an A-shaped slot along the underside of the vehicle. The slot dimensions will be approximately: height = 50 cm, angle = 45 degrees. The height of a RUF will be 165 cm. The width will be 175 cm. The length of a 2-person RUF will be 340 cm total (300 cm in a train, close coupled with other RUFs). A 4-person RUF will be a little longer. Ideally, the front and rear of the vehicles are identical in shape to allow close coupling.
On normal roads, the RUF functions as a normal electric car. The batteries are smaller because the RUF uses the rail when it drives long distances. On the rail, the RUF takes current from the rail so the batteries can be charged during rail travel. Normally the rail travel is fast, so the time is too short for a complete recharge of the batteries. In the case of a rail power supply breakdown, the RUF train can continue at reduced speed with power from the batteries. If the user needs to go to a place a long distance from the rail system, the 50 km range may be too short. In this case, the driver can use a special hybrid unit which can be mounted under the RUF. It fits into the A-shaped slot along the underside of the vehicle. It contains an ICE motor running at constant speed, optimized for maximum efficiency and low pollution. The motor drives a generator which makes electric power for the RUF. The hybrid unit has a gasoline tank with sufficient volume so that the hybrid RUF has the same range as a normal car.
On normal roads, it can brake precisely as a normal car. Compared to a normal electric car, the weight is lower because of the smaller batteries, so the kinetic energy is lower and less energy is wasted during braking. If future batteries are able to absorb large charging currents, the RUF will be able to make use of the kinetic energy by using the motor as a generator and charge the battery. On the rail, it can use regenerative braking because the rails can absorb the large currents. As long as everything is working normally, every braking situation will be controlled and the rail wheels will never be blocked. The wheels can be smooth rubber wheels without brake linings. The rolling resistance can be low and the noise from the wheels running on the smooth surface of the rail will be very low. In case of an emergency situation, the RUF has a special rail-brake which can bring the RUF to a complete stop in a very short time. The rail-brake can put pressure on the sides of the rail. It is placed so that it acts on the top of the triangular rail. Normal braking systems are limited by the weight of the vehicle, which directly affects the friction force between the wheel and road/rail. There is no limit to the amount of friction which can be obtained with the RUF rail-brake. If the passenger can withstand -1g as a maximum deceleration during emergency braking, the RUF can go from 100 km/h to a complete stop in 40 m. A car needs 150 m and a train needs a much longer distance. The consequence is that the RUFs can drive with relatively short distances between trains, so the capacity is high. The rail-brake is located at the ideal position relative to the center of gravity of the RUF vehicle. This means that the RUF is completely stable during braking, unlike cars on the road.