Not Your Father’s Public Transport

The future of sustainable motorized transportation may resemble
a driverless fully-enclosed golf-cart zipping 16 feet above the
streets of North America’s cities. Known by lots of names — Skyweb
Express, Taxi 2000, MicroRail, Higherway, and Skycab — personal
rapid transit (PRT) is a system for moving people in a way similar
to how networked computers move bits of information around the
Internet. PRT developers envision a system that combines the
automobile’s direct destination-to-destination convenience and
privacy with public transit’s capacity to reduce pollution, unclog
traffic, and serve low-income communities.

The PRT idea has been around for decades, but now modern
computer power is bringing it closer to reality. One prototype
being demonstrated in suburban Minneapolis by the Taxi 2000 company
features Jetsons-looking PRT cars that travel on narrow elevated
‘guideways.’ If a full system was built, the guideways would
criss-cross a metropolitan area giving commuters a direct route to
their destination. Though some cars are designed to hold as many as
six people, PRT at heart is a private form of transit. A rider
finds a station, selects a destination, and enters a car, leaving
it to the computers to weigh the options and determine the best
path. Route maps and schedule tables are unnecessary; the entire
operation is designed around individual demand. Proponents say
there will be no traffic jams, no gridlock, and no accidents
because merging to and exiting to and from off-line stations will
all be controlled automatically.

Because the cars are simple and lightweight, the guideways can
be small and cheap and installed with minimal disruption. According
to J. Edward Anderson, CEO of Taxi 2000, guideway systems can be
built for $10 million per mile, an exceptionally low cost when
compared with highways ($20 million) and light rail ($70 million).
(A University of Washington study has estimated an even lower price
tag for a metropolitan PRT system-about $5.5 million per mile.)
Supporters note that PRT’s lower cost per mile allows it to better
serve spread-out communities. The higher cost of conventional rail
means that subways and light rail serve only narrow corridors while
PRT can fan out through a region.

PRT does have its critics, including those who question its
basic feasibility and voice concerns about safety at stations and
the aesthetic impact of building overhead guideways throughout a

PRT supporters respond that in a current design, the elevated
PRT guideways are three feet square and can be built on streets and
alleys and even through buildings. As a result, the system eats up
less real estate than our current automobile infrastructure, which
now accounts for more than half the land in many city centers. It’s
predicted that a single narrow PRT guideway could carry roughly the
same capacity as a four-lane highway.

For more information on personal rapid transit, contact
Citizens for Personal Rapid Transit

Michael Fraase is Utne’s Webmaster.

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