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TABLE F.1 Carbon Dioxide Emissions by Commuting Mode
(tons/year)
|
|
Mode
|
Btu per Passenger Milea
|
Yearly Energy (MBtu)b
|
Equivalent Gallons Gasolinec
|
Amount of Yearly CO2 Emissionsd
|
Difference from Solo Driving
|
|
Solo driving
|
8,333
|
41.66
|
333.3
|
2.98
|
—
|
|
Bus
|
2,121
|
14.77
|
118.2
|
1.06
|
1.92
|
|
Rail
|
1,935
|
13.84
|
110.7
|
0.99
|
1.99
|
|
Carpool
|
3,788
|
18.94
|
151.5
|
1.36
|
1.62
|
|
Vanpool
|
882
|
8.58
|
68.6
|
0.61
|
2.37
|
|
aFor solo
drivers, the figure is per vehicle-mile for automobile
commuting.
|
|
bEnergy
use = (Btu per passenger-mile) × (10 miles per commuting
trip) × (2 trips per day) × (250 commuting days per
year). In addition, for bus, rail, and vanpool modes, it is assumed
that commuters drive alone 1 mile (at 8333 Btu/mi) each way per day
to get to the transfer point. For rail, energy use for commuter
rail is used (rather than the lower energy use for transit
rail).
|
|
cAssumes
that 1 gallon of gasoline = 125,000 Btu (Davis et al., 1989).
|
|
d(Gasoline
usage) × (19.7 lbs CO2/gal
gasoline)/(2200 lb/t).
|
|
parking spaces are eliminated, it is assumed that none of the 9
million displaced solo commuters continue to drive alone, and all
are divided among the four remaining modes. Where parking spaces
are priced to reduce the solo driver mode share to 50 percent, the
shares for the remaining modes are proportional to those calculated
for elimination of parking spaces. (To account for the remaining
solo drivers, the other mode shares add up to 50 percent, rather
than 100 percent, of all commuters.) The mode splits for displaced
drivers are presented in Table F.2.
These mode splits are then applied to the 9 million solo drivers
affected by the parking elimination component and the 27 million
solo drivers affected by the parking management component. As shown
in Table F.3, the combination of these two measures would produce
annual emission reductions of 49 Mt of CO2.
Calculation of Cost-Effectiveness
A parking demand management program of the type described in
this appendix would involve several types of costs and savings:
• employees' out-of-pocket costs or savings from the use of
alternative transportation modes (a figure that includes fuel
savings);
• employers' out-of-pocket operational costs or savings
from parking management and provision of transportation
alternatives;
