The guideway is often the most expensive part of the initial cost for a transit system. The Higherway guideway has several features to keep the life cycle cost as low as possible:
Different support techniques will be used in different locations. An example for an urban one-way guideway is shown on the left below. The track on the left is for accelerating vehicles, the track on the right has a line speed of 45 meters per second (100 mph) except on steep hills and curves. A rural two-way guideway is on the right below. The Pelican on the left is coming toward you, the Dove on the right is going away from you. It uses smaller support poles and more of them to reduce foundation and structure costs. Because it is farther from stops it doesn't need acceleration tracks.
The track is made of roll-formed and corrosion-protected steel. See cross-section drawing.
This drawing is for spans up to 24 m. Longer spans will be taller or have additional structures supporting the tracks. Some other drawings on this website show an older design for short spans (ramp tracks) and without the utility duct. Not shown in the cross section drawing are holes in the upper part of the track to reduce loads from cross winds, the junctions between track sections, and stiffeners which may be needed periodically to prevent deflection of the track.
The Higherway track goes over and around the bogie part of the vehicles. This is advantageous for quick vehicle switching and to provide a clean, dry running surface for the tires. However, since it is a high-speed (up to 45 m/s) suspended system in merge/diverge Y-sections one side of the tires will not be supported and means must be provided to keep the bogies from falling through the gap in the bottom of the track. Higherway guideways will have more Y-sections than most other systems because there will almost always be acceleration tracks next to the high-speed tracks to enable merging without slowing the vehicles on the main high-speed tracks.
Requirements on the track and bogie for going through merge/diverge Y-sections of track:
1. The bogies must not overturn and fall through the track. a. stabilizer wheels on the bogie must be engaged and locked in place by the bogie and track before the bogie enters the Y-section. b. the bogie must interact with the track before a diverge Y-section to force the bogie mechanical switch to either the left or right position. c. the track must force the bogie stabilizer wheels to run on the outside edge of the track and lock in place before a merge Y-section.
2. There will be at least four track cross-sections:
3. The track/bogie interactions have to work correctly to allow the bogies to navigate and not overturn and fall through the track if the bogies are going backwards. (They go backwards to exit dead-end spurs and to clear the track in case of line blockage.) Approaching a diverge Y the track would go from a to d to c to b to a. Approaching a merge Y the track would go from a to b to c to d to a. The drawings above illustrate the added complexity and precision required for track sections b, c, and d. Section c is the most critical because it is where there is the possibility of merge collisions and bogies falling to the ground. We expect careful design of shock absorbers in the track (not shown in drawing) and thorough development testing to reduce this hazard to a negligible level.
Different support structure is needed for Y sections in urban areas to allow the vehicles to cross over between acceleration tracks and through tracks without hitting the support poles. An example is in the drawing below.
The current plan for the manufacturing process is:
In some locations stainless steel will be the most economical
choice for the track material. For stainless, steps 7 and 8 above may be
omitted unless painting is still required for aesthetic reasons.
Higherway guideways can be added to many existing bridges at relatively low cost because:
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This page last updated June 1, 2003