A bit about the Technical Aspect
The following image shows a conceptual cross-section view of the guideway and bogies1.
Of note is the use of a single I-Beam for two levels of podcars which maximizes material use over the span length. I-beams are also common structural elements that don’t require special welding, bending or cutting to fabricate which keeps cost low. Cross-bracing improves torsion resistance and provides supporting elements for an emergency walkway option. The lower level can have short “porches” at columns which allows access to the main walkway via a hatch and ladder and to the lower vehicle via podcar window and “limp” mode. The walkway is meant mainly to facilitate rescue in a severe earthquake class scenario as it is generally safer to remain in the podcar. Exact procedures depend on many factors.
Steel wheel on steel tracks support the vehicle’s weight. Steel wheels were chosen because of their low rolling resistance, durability and as with all wheels, no energy use when stopped, unlike maglev which uses a proportionally large amount of energy at low speeds. In order to avoid small wheels that wear quickly and that are limited in speed, a linear motor holds the vehicle laterally along with the steering mechanism for the wheels. Propulsion is by linear motor which provides traction and also regenerative braking in any weather.
High-Speed mode does not use electric power rails as are used in higher-speed and regular sections, saving some infrastucrure expense, nor does it use linear motors for propulsion, only for centering. It uses batteries or hydrogen for energy and relies on traction for propulsion.
A design goal for Lofty Taxi is to be a BRT or LRT drop-in replacement. This means throughput must be quite high for PRT. In order to achieve this goal and still meet APM standards, a few changes are necessary. Two lines doubles troughtput, one is for two passenger podcars and the other is for four. Another way to increase thoughput is to run podcars in tandem “trains”. By designing for tandem podcars, double-length “stretch” podcars can also be accomodated. Gap-closing won’t meet APM standards, but forming “trains” at low speeds does, the same way railway cars are assembled. Since PRT has the ability to independentlly choose a path at a diverge, each podcar is either on its own path or they remain in train formation which means that spliting up tandem trains is always possible. So even with just shy of two seconds headways, 8,000 vph are possible and with an average vehicle occupancy of 1.3, we get 10,000 people per hour per direction which is 20,000 people per hour (in two direction) and this comprares very favourably with BRT and LRT numbers.
An interesting concept under investigation is called the “Transmodal Capsule”2 which describes a system where a capsule (or cargo) is transfered from mode to mode. This is in contrast to the modal transit model where patrons are required to transfer with all the inconveniences implied. To enable this Transmodal paradigm, a method of transfer for cabins and cargo must be defined. Fortunately, such a method exists in the airline industry where ULD3 are used. With such an interface, we can envision a transfer from PRT to a driverless car as Google4 champions, on an electric chassis of repute like Tesla’s Model-X5. Other modes for transfer might include planes, trains, Hyperloop6, boats and elevators.
1 Bogies are the rolling mechanisms under/over the main podcar bodies and are inside the guideway covers.
2 Transmodal capsule: http://faculty.washington.edu/jbs/itrans/tmcap.htm
3 Unit Load Device: http://en.wikipedia.org/wiki/Unit_load_device
4 Google Car: http://www.google.com/selfdrivingcar/
5 Model-X: http://www.teslamotors.com/modelx
6 Elon Musk invented the Hyperloop: http://www.spacex.com/hyperloop