Monorails and virtually all of the recent innovative
fixed-guideway concepts are mainly used in "shuttle loop"
applications and have few prospects for widespread usage as in
urban networks. The reason is due primarily to their lack of a
simple, compact and reliable switch suitable for two-way traffic.
System 21 provides such a switch and more, offering grade
separated branching which avoids collisions and interlocking delays.
The figures above and below depict the cornerstone
of System 21's approach to grade separated branching, the
switch module. A moveable rail section queues the vehicle for
either a 15 mph diverging route to a branch line, or a 35 mph
main line routing. A 9-foot moveable frog rotates a section of
top rail into place to accommodate the outrigger for a main line
routing, or a section of bottom rail to accommodate the vehicle's
lower drive wheels for a diverging route.