Environmental Engineering Reference
In-Depth Information
12.1 Personal rapid transit
The history of PRT goes back to at least the nineteenth century, and since about
1953 work in this area has been almost continuous, mainly promoted by individuals
and small companies around the globe [4]. One of the strongest advocates of PRT,
J. Edward Anderson, at one point met with and advised the then President Richard
Nixon on the benefits of such systems. The result of this meeting became clearer in
President Nixon's speech to Congress in January 1972 when he announced a fed-
eral PRT development programme. Coming on the heels of the successful Apollo
mission to the moon, it was believed that PRT was indeed feasible and that funding
would make this a reality. It turned out that going to the moon was far easier.
In 2009, for the first time in history, the number of people living in cities
around the globe surpassed the number of people living in rural areas. Traffic
congestion has been a concern for decades in large metropolitan areas, and con-
tinues to aggravate at some places. PRT advocates point to congestion and other
concerns when touting the merits of their systems. Often cited reasons to imple-
ment PRT are the rationale summarized by Anderson [5] and repeated here for
reference:
Increased congestion
●
Dependence on oil imports
●
Global warming
●
Excessive energy consumption used in transportation
●
The shear number of people killed in auto accidents each year
●
Add to this: excessive sprawl, terrorism, land used for parking
●
Cost of PRT is always on the rise. Thornton
et al.
[6] note that where public
transit systems in use today cost on the order of $70M/km, a small, 4-passenger
PRT can be put in place for approximately $24M/km. Specifics on the PRT car
size are given in Table 12.2.
Table 12.2 Characteristics and parameters for PRT
Parameter
Unit
Characteristic
Maximum speed on level track
mph
24
Capacity, at maximum loading of 500 kg
# persons
4
Vehicle length on track
m
3.7
Vehicle width,
W
, and height,
H
(
W
/
H
)
m
1.45/1.6
Turning radius
m
5
Track slope limits (upgrade/downgrade)
%
20/6.25
Continuous power on level track
kW
2
Energy consumption per unit capacity per km
MJ/passenger/km
0.55
Compared with other forms of personal transport or mass transit, the PRT
system according to Lowson [7] has the lowest energy consumption per unit
