Masdar City’s pedestrian-focused, walkable design showcases continuous
shaded areas for walking and human-scaled urban design features. The city’s
transportation system is made up of electric cars, electric buses and the PRT
pods buried underground. Masdar City’s PRT system has attracted much attention,
as it was one of the only systems in the world designed on such a large scale. A
light rail line and Metro lines will eventually connect the city center to Abu
Dhabi. Cars are not allowed inside the city but are limited to parking lots at
the edge of the city, close to future light rail lines.
So, what is Personal
Rapid Transit, anyway?
It is an emerging transportation mode that uses
small, computer-guided ‘podcars’ to move groups of 3-6 people between stations
on a dedicated network of guide-ways. These vehicles are driverless and operate
on-demand, eliminating the need for actual cars. Since the PRT systems are
computerized, the cars can by-pass crowded stations, reaching its destination
in an efficient manner. Currently, there is a working prototype in Masdar City;
the city had to be lifted on a pedestal to accommodate the PRT.
Although there are a few PRT systems being implemented, the
only other functioning PRT system in the world is in the London Heathrow
Airport, known as ULTra
(Urban Light Transit) with a fleet of 21 cars on elevated tracks. This system
serves as a connector between Terminal 5 and its associated parking lots,
reaching speeds up to 25kmph (15.5 mph). Already, this system is being credited
with using 50% less energy than the diesel burning buses it replaced.
PRT has enamored many academic endeavors as well. Students
at Princeton University produced a report
on the feasibility of implementing PRT on a statewide scale! University of
Washington has a huge online resource
that has the most updated research on PRT and an active debate going on about
its benefits.
However, I think their scope is best limited to a smaller
scale. I see their implementation to be especially useful on university
campuses (1), airports, large hospitals, and neighborhoods – areas that are
similar in size to Masdar City and where there is an aspect of self-sufficiency
within the campus or neighborhood. This gives rise to the idea of PRT being a
possible solution for the last mile issue by serving as local collectors of a light
rail line. Andreasson explored this issue in a feasibility study paper and
concluded that functions such as ticketing, vehicle scheduling, and station design, were critical to the success of PRT (2).
Can PRT really make a car-free city work?
As fantastic as this idea of a sustainable city, like Masdar
City, seems to be, the city itself has been widely criticized as a futuristic,
high-end ‘enclave’ that caters only to the rich
with many skeptics are calling it the “Cancer City”.
Moreover, the extreme costs of expanding the PRT prototype, led the city to scrap
the project entirely.
Critics of the PRT are very vocal and their
opinions are not limited to its application in a ‘sustainable city’. Tahmasseby
and Kattan’s TRB paper outlines some major concerns of PRT. The PRT system has
been deemed too
small to meet passenger load demands of an actual city, especially in the
central city areas. Moreover, there is a dearth of research on its better
integration in urban environments – whether it works as a stand-alone or integrated with larger mass transit systems. There are also reliability issues
- concerns about performance and emergency situation management in extreme
weather. Lastly, it being such a new system and yet to be regulated technology, there is
a lack of consensus on whether to apply rail regulations or to apply personal
vehicle regulations.
That said, I think the problems arising from PRT are similar
to both the electric and the Driverless Car. According to J. Edward Anderson,
faculty member at University of Washington, the PRT system, if unregulated
early on, has a very real potential to
contribute to further sprawl, as the PRT takes away all the inconveniences
of a car forcing development to move further out. Adding to that is their requirement for a
whole network of guide-ways that are superimposed on the existing street
network, or raised above ground, effectively disrupting visual access and
appeal of urban environments.
PRT is a radical solution to an age-old problem. Given that
the PRT is such a new technology, it is hard to say what the future will look
like. In its current state, implementing PRT in our communities can be
extremely cost prohibitive and full of challenges. They are envisioned to start to solve a
regional issue but I think will eventually end up as a specialized local
solution, at least until there are huge leaps in innovation, greatly reducing
its costs and feasibility issues.
Sources
(1) Dr. Shahram Tahmasseby, Dr. Lina Kattan. Investigating economic viability of a personal rapid transit (PRT) system for a university campus and its surroundings. TRB Annual Meeting 2013. July 2012.
Juster, R. (1954). A comparative analysis of personal rapid transit as an urban transportation mode (pp. 1–17).
Alessandrini, A., & Stam, D. (2013). PRT studies in two Scandinavian cities (Vol. 6938, pp. 1–14).
Proactive empty vehicle redistribution for personal
rapid transit and taxis, John
D. Lees-Miller, R. Eddie Wilson , Transportation
Planning and Technology , Vol. 35, Iss. 1, 2012
Other Sources:
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