Civil Engineering Reference
In-Depth Information
Table 13.8
Congestion cost estimate summary table
—
selected studies
Publication
Costs
Cost value
2007 USD
Delucchi (1997)
Total US in 1991
$34
-
146 billion
(1991)
$52
-
222 billion
Per urban peak mile
$0.07
0.32
$0.11
0.49/
-
-
mile
Lee (2006)
US traffic congestion delay
costs, relative to free
$108 billion
(2002)
$124 billion
fl
flowing
traffic
Delay costs based on
willingness to pay
$12 billion
$14 billion
TRB (1994)
Congested urban roads per
vehicle mile
Average of $0.0
10
-
0.15*
$0.14
-
0.21/
mile
Texas
Transportation
Institute (2007)
Total US in 2005
$78.2 billion
(2005)
$83 billion
Winston and
Langer (2004)
Total US congestion costs
$37.5 billion
(2004)
$41 billion
Land Transport
New Zealand
(2005)
Bene
ts of TDM mode shift
per
km
SI.27
-
Auckland,
$1.09/mile
$0.98
-
Wellington,
$0.84/mile
$0.09
Cri5tchurch
(NZ$2002/Km)
$0.08/mile
-
FHWA (1997)
Urban Highway Car
$0.062/VMT*
$0.08/mile
Bus
$0. 128
$0.17
Maibach et al.
(2008)
Urban collectors in European
centres over 2 million
0.5
/vkm 2000
$0.89/mile
€
—
Car
Truck
1.25
$2.23
€
*
indicates the currency year is assumed to be the same as the publication year
Source
Reference [
23
], pp 5.5-15, Table 5.5.4-1
decreasing city size, producing different conclusions for each city as to the amount
of congestion associated with an actual congestion speeds of 30 mph (Table
13.10
).
This example shows that important role played by the different threshold value
of congestion, in calculating its magnitude. Congestion cost estimates are often
developed using different congestion thresholds and different assumptions/methods.
When comparing the results of different studies it is vital to state the assumptions
used in measuring congestion delay. The need to clarify the assumptions inherent in
congestion delay calculations is critical in interpreting its signi
cance in trans-
portation decision making.
13.2.1.5 Traf
c Crashes and Traf
c Congestion
Many roadway design features and operating practices not only increase conges-
tion, but they also increase traf
c crashes. Freeway designs such as short weaving
distances, inadequate ramp lengths, and left-hand access points create con
fl
icts and
