Projecting how many existing auto trips will be diverted to
HSR is a three step process.
-- Determine how many of the trips between each
city pair are made by auto. Data is derived from the American Travel Survey
from the Bureau of Transportation Statistics.
- -
Compare the relative percentage of all trips
made by auto and air to the (already known) number of air passengers between
each city pair. Data on air passengers is from the T-100 report from the Bureau
of Transportation Statistics.
- -
Adjust the number of auto trips to account for
population growth. Data is from the Census Bureau.
For city pairs in which there were no regularly scheduled
flights, I used the average rate of auto trips per population among other city
pairs on the same corridor. The first chart shows the mode share of autos and
the estimated number of auto trips for each city pair on the 5 regional
corridors.
|
Corridor
|
City 1
|
City 2
|
% of trips by auto
|
Estimated Auto Trips
|
|
|
ATL
|
Greenville
|
91.2
|
8139803
|
|
|
ATL
|
Charlotte
|
82.6
|
4866432
|
|
|
Charlotte
|
Raleigh
|
93.2
|
3132800
|
|
|
Greensboro
|
ATL
|
53.5
|
314074
|
|
|
Greensboro
|
Charlotte
|
93.3
|
7751661
|
|
SOUTHEAST
|
Greensboro
|
Raleigh
|
97.6
|
2563200
|
|
|
Greensboro
|
Greenville
|
100
|
1922400
|
|
|
Greenville
|
Charlotte
|
96.7
|
4142966
|
|
|
Greenville
|
Raleigh
|
90.9
|
3586
|
|
|
Raleigh
|
ATL
|
59.6
|
953420
|
|
|
|
|
|
|
|
|
Austin
|
Houston
|
93.4
|
9911771
|
|
TEXAS
|
Houston
|
San Antonio
|
69.4
|
1154133
|
|
|
San Antonio
|
Austin
|
100
|
2788000
|
|
|
|
|
|
|
|
|
Chicago
|
Indy
|
57
|
523232
|
|
|
Chicago
|
Cincinnati
|
64.6
|
450361
|
|
|
Indy
|
Cincinnati
|
92.8
|
152592
|
|
|
Indy
|
STL
|
71.6
|
1707
|
|
|
Milwaukee
|
Chicago
|
92.7
|
412692
|
|
MIDWEST
|
Milwaukee
|
Indy
|
66.6
|
35067
|
|
|
Milwaukee
|
Cincinnati
|
25
|
12161
|
|
|
STL
|
Cincinnati
|
73.9
|
118908
|
|
|
STL
|
Chicago
|
69.4
|
1907415
|
|
|
STL
|
Milwaukee
|
48.4
|
62784
|
|
|
|
|
|
|
|
|
Cleveland
|
Detroit
|
88.7
|
1050823
|
|
GREAT LAKES
|
Detroit
|
Pitt
|
80
|
667919
|
|
|
Pitt
|
Cleveland
|
97.2
|
1158030
|
|
|
|
|
|
|
|
|
Tampa
|
Miami
|
60
|
605754
|
|
FLORIDA
|
Orlando
|
Tampa
|
96.7
|
2420000
|
|
|
Orlando
|
Miami
|
77.7
|
9588047
|
Since the number of people traveling by auto is much higher
(an average of 78% of all trips), the pool of potential riders is higher than
air travelers.
In order to predict how many of the travelers who are now
driving will switch to HSR, we have to look at the value of time. US Department
of Transportation guidelines for assessing the value of time in travel
recommend 70% of the hourly equivalent a household’s income11. The
median household income nationwide is about $50,000. That is an hourly
equivalent (at 40 hours a week, 52 weeks per year) of $24.03. 70% of that value
is $16.80 per hour, or 28 cents per minute. So on average, a traveler is
willing to pay 28 cents extra for each minute of time saved. If a trip takes 3
hours to drive and 2 hours by rail, that is $16.80 in addition to the cost of
driving, which is about 20 cents per mile3.
Since the value of time is dependent on income, the
willingness to pay more to save time increases for higher income households.
Using data on income distribution13, I calculate the percentage of
travelers with incomes high enough to justify paying the additional cost of a
rail ticket. For some routes (St. Louis-Chicago) nearly half of drivers will
switch to rail. For other routes (such as Chicago-Indianapolis) only 2 percent
of drivers are likely to switch.
The time saved and cost required is different for each city
pair. Thus, the income required to have a value of time high enough so that the
value of the time saved is greater than the additional cost of rail over
driving differs for each route.
|
Corridor
|
City 1
|
City 2
|
Estimated Auto Trips
|
% of Auto Travelers with
Net Benefits
|
Projected Riders
|
|
|
ATL
|
Greenville
|
8139803
|
2
|
440415
|
|
|
ATL
|
Charlotte
|
4866432
|
15
|
281962
|
|
|
Charlotte
|
Raleigh
|
3132800
|
7
|
994000
|
|
|
Greensboro
|
ATL
|
314074
|
6
|
18011
|
|
|
Greensboro
|
Charlotte
|
7751661
|
5
|
227738
|
|
SOUTHEAST
|
Greensboro
|
Raleigh
|
2563200
|
19
|
955789
|
|
|
Greensboro
|
Greenville
|
1922400
|
7
|
264100
|
|
|
Greenville
|
Charlotte
|
4142966
|
32
|
3810970
|
|
|
Greenville
|
Raleigh
|
3586
|
32
|
299
|
|
|
Raleigh
|
ATL
|
953420
|
10
|
62609
|
|
|
|
|
|
|
|
|
|
Austin
|
Houston
|
9911771
|
25
|
2446748
|
|
TEXAS
|
Houston
|
San Antonio
|
1154133
|
0
|
0
|
|
|
San Antonio
|
Austin
|
2788000
|
11
|
298102
|
|
|
|
|
|
|
|
|
|
Chicago
|
Indy
|
523232
|
2
|
7528
|
|
|
Chicago
|
Cincinnati
|
450361
|
0
|
0
|
|
|
Indy
|
Cincinnati
|
152592
|
0
|
0
|
|
|
Indy
|
STL
|
1707
|
0
|
|
|
|
Milwaukee
|
Chicago
|
412692
|
13
|
71311
|
|
MIDWEST
|
Milwaukee
|
Indy
|
35067
|
4
|
28
|
|
|
Milwaukee
|
Cincinnati
|
12161
|
0
|
0
|
|
|
STL
|
Cincinnati
|
118908
|
0
|
0
|
|
|
STL
|
Chicago
|
1907415
|
49
|
827982
|
|
|
STL
|
Milwaukee
|
62784
|
9
|
7997
|
|
|
|
|
|
|
|
|
|
Cleveland
|
Detroit
|
1050823
|
22
|
549311
|
|
GREAT LAKES
|
Detroit
|
Pitt
|
667919
|
19
|
147099
|
|
|
Pitt
|
Cleveland
|
1158030
|
22
|
1500869
|
|
|
|
|
|
|
|
|
|
Tampa
|
Miami
|
605754
|
32
|
49248
|
|
FLORIDA
|
Orlando
|
Tampa
|
2420000
|
9
|
403714
|
|
|
Orlando
|
Miami
|
9588047
|
7
|
497958
|
Now, I add in the air travelers discussed previously, to
find the total ridership for each city pair.
|
Corridor
|
City 1
|
City 2
|
Total Projected Riders
|
|
|
ATL
|
Greenville
|
612636
|
|
|
ATL
|
Charlotte
|
2151426
|
|
|
Charlotte
|
Raleigh
|
1769192
|
|
|
Greensboro
|
ATL
|
18011
|
|
|
Greensboro
|
Charlotte
|
619624
|
|
SOUTHEAST
|
Greensboro
|
Raleigh
|
955789
|
|
|
Greensboro
|
Greenville
|
264100
|
|
|
Greenville
|
Charlotte
|
3902826
|
|
|
Greenville
|
Raleigh
|
1060
|
|
|
Raleigh
|
ATL
|
62609
|
|
|
|
|
|
|
|
Austin
|
Houston
|
3425106
|
|
TEXAS
|
Houston
|
San Antonio
|
973384
|
|
|
San Antonio
|
Austin
|
298102
|
|
|
|
|
|
|
|
Chicago
|
Indy
|
816412
|
|
|
Chicago
|
Cincinnati
|
0
|
|
|
Indy
|
Cincinnati
|
0
|
|
|
Indy
|
STL
|
0
|
|
|
Milwaukee
|
Chicago
|
430434
|
|
MIDWEST
|
Milwaukee
|
Indy
|
18768
|
|
|
Milwaukee
|
Cincinnati
|
0
|
|
|
STL
|
Cincinnati
|
0
|
|
|
STL
|
Chicago
|
2377748
|
|
|
STL
|
Milwaukee
|
125918
|
|
|
|
|
|
|
|
Cleveland
|
Detroit
|
661071
|
|
GREAT LAKES
|
Detroit
|
Pitt
|
385172
|
|
|
Pitt
|
Cleveland
|
1523858
|
|
|
|
|
|
|
|
Tampa
|
Miami
|
581730
|
|
FLORIDA
|
Orlando
|
Tampa
|
403714
|
|
|
Orlando
|
Miami
|
1582678
|
And here is the total high speed rail ridership for each
corridor.
|
Corridor
|
Total Riders (M)
|
|
Texas
|
4.69
|
|
Florida
|
2.56
|
|
Southeast
|
10.35
|
|
Great Lakes
|
2.57
|
|
Midwest
|
3.76
|
|
TOTAL
|
23.93
|
These projections are conservative, in that they are based
on current, actual numbers of travelers. Also, they do not include any new
travelers. Some individuals who would choose not to travel if air and auto were
the only options, may choose to travel at the price point offered by HSR. This
analysis also does not take into account future increases in energy prices,
which are likely to increase the cost of air and auto travel more than rail.
