11/1/1999
Why are the Roads so Congested? Population Growth and Congestion: Perception Vs. Reality
Back
to Table of Contents
As shown by the Texas Transportation
Institute, drivers are experiencing increasingly congested road conditions. This crowding
on the roads is often attributed to a region’s growth. Yet TTI’s data shows that
population in the metro areas studied has grown by an average of 22% in the 16 years since
1982, while the average traffic delay experienced by individuals has increased 235% in the
same period. Obviously, something else is going on.
That something else is the increase in
driving, most of it necessitated by our sprawling pattern of development. According to
TTI, the amount Americans drive every day has grown by about 70% since 1982. This makes it
feel as if the roads are bursting at the seams with new drivers. In fact, the roads are
mostly filled with the original residents, who are simply driving farther and more often.
The chart below shows how the increase in
driving per person magnifies population growth and affects the crowding on the roads in
the metro areas with the worst rush-hour congestion. For example, in Los Angeles,
California, the population grew by 2.4 million since 1982. But the 56% increase in driving
made it seem as if 5.5 million additional drivers were on the road. This ‘perceived
population growth’ on the roads helps explain why our highways are so congested.
Table 1. Actual and Perceived Population
Growth (1982 to 1997)
| TRI
Rank1 |
Metro Areas2 |
Percent
Change in Population |
Percent
Change in Driving |
Actual
Population Growth |
Perceived
Population Growth |
1 |
Los
Angeles CA |
24.2% |
56.0% |
2,400,000 |
5,544,978 |
2 |
Seattle-Everett
WA |
36.1% |
68.9% |
520,000 |
992,230 |
3 |
San
Francisco-Oakland CA |
18.5% |
43.1% |
610,000 |
1,419,150 |
4 |
Washington
DC-MD-VA |
28.3% |
77.4% |
765,000 |
2,088,576 |
5 |
Chicago
IL-Northwestern IN |
12.7% |
87.9% |
900,000 |
6,220,291 |
6 |
Atlanta GA |
60.2% |
138.6% |
970,000 |
2,231,840 |
6 |
Miami-Hialeah
FL |
19.7% |
67.2% |
340,000 |
1,163,042 |
8 |
Boston MA |
5.8% |
32.3% |
165,000 |
919,836 |
9 |
Detroit MI |
5.4% |
46.0% |
205,000 |
1,753,198 |
9 |
Las Vegas
NV |
155.6% |
182.9% |
700,000 |
823,256 |
9 |
San Diego
CA |
46.6% |
84.1% |
830,000 |
1,496,694 |
Overall since 1982, population in the 68 metro areas
studied has grown by 22 million people. However, because of the huge increase in driving,
it feels as though about 70 million more drivers are on the highways in these metro areas.
This is more than three times the actual population growth. The next page shows the
perceived population growth for the rest of the cities studied by the Texas Transportation
Institute, as ranked by TTI’s measure of rush-hour congestion, the Travel Rate Index.
Table 1. Cont’d
| TRI
Rank1 |
Metro Areas2 |
Percent
Change in Population |
Percent
Change in Driving |
Actual
Population Growth |
Perceived
Population Growth |
12 |
Houston TX |
29.2% |
71.7% |
700,000
|
1,721,493
|
12 |
New York
NY-Northeastern NJ |
3.0% |
42.7% |
500,000
|
7,106,903
|
12 |
Portland-Vancouver
OR-WA |
32.7% |
107.5% |
330,000
|
1,085,780
|
15 |
San Jose CA |
35.0% |
59.9% |
420,000
|
719,081
|
16 |
Denver CO |
33.3% |
64.6% |
450,000
|
872,117
|
16 |
Phoenix AZ |
67.8% |
130.7% |
970,000
|
1,868,916
|
16 |
San
Bernardino-Riverside CA |
43.9% |
78.1% |
415,000
|
738,362
|
19 |
Minneapolis-St. Paul
MN |
30.9% |
105.7% |
540,000
|
1,849,919
|
19 |
Tacoma WA |
40.5% |
69.8% |
170,000
|
293,002
|
21 |
Dallas TX |
28.2% |
82.2% |
510,000
|
1,488,533
|
21 |
Ft.
Lauderdale-Hollywood-Pompano Beach FL |
40.8% |
96.0% |
435,000
|
1,022,901
|
21 |
Sacramento CA |
48.8% |
82.7% |
405,000
|
686,090
|
21 |
St. Louis MO-IL |
9.7% |
73.3% |
180,000
|
1,356,168
|
25 |
Austin TX |
65.8% |
174.4% |
250,000
|
662,531
|
25 |
Baltimore MD |
26.5% |
67.6% |
450,000
|
1,148,363
|
25 |
Charlotte NC |
64.3% |
160.8% |
225,000
|
562,689
|
28 |
Cincinnati OH-KY |
12.4% |
66.8% |
140,000
|
754,807
|
28 |
Honolulu HI |
23.7% |
56.1% |
135,000
|
319,898
|
28 |
Indianapolis IN |
17.4% |
103.4% |
150,000
|
889,524
|
28 |
Philadelphia PA-NJ |
29.5% |
45.9% |
1,200,000
|
1,869,502
|
28 |
Salt Lake City UT |
32.4% |
100.5% |
220,000
|
683,568
|
33 |
Columbus OH |
21.6% |
92.9% |
180,000
|
775,729
|
33 |
Milwaukee WI |
3.7% |
54.9% |
45,000
|
664,338
|
35 |
Orlando FL |
75.4% |
184.5% |
460,000
|
1,125,589
|
36 |
Albuquerque NM |
28.4% |
100.7% |
125,000
|
443,003
|
36 |
Louisville KY-IN |
9.7% |
106.0% |
75,000
|
815,917
|
36 |
New Orleans LA |
3.7% |
53.6% |
40,000
|
578,682
|
36 |
Tampa FL |
53.7% |
139.8% |
290,000
|
754,898
|
36 |
Tucson AZ |
44.4% |
183.7% |
200,000
|
826,550
|
41 |
Cleveland OH |
6.9% |
59.0% |
120,000
|
1,031,649
|
41 |
Norfolk VA |
32.5% |
73.0% |
250,000
|
561,863
|
43 |
Memphis TN-AR-MS |
27.6% |
91.8% |
210,000
|
697,376
|
44 |
Fort Worth TX |
19.8% |
80.0% |
215,000
|
868,177
|
44 |
Omaha NE-IA |
12.0% |
83.2% |
60,000
|
416,021
|
46 |
San Antonio TX |
29.5% |
66.7% |
280,000
|
634,044
|
47 |
Jacksonville FL |
34.1% |
73.4% |
210,000
|
451,137
|
48 |
Fresno CA |
56.5% |
43.7% |
195,000
|
150,612
|
48 |
Nashville TN |
26.0% |
130.4% |
130,000
|
652,206
|
48 |
Providence-Pawtucket
RI-MA |
9.1% |
62.1% |
75,000
|
512,225
|
51 |
Colorado Springs CO |
48.2% |
65.2% |
135,000
|
182,519
|
52 |
Hartford-Middletown CT |
13.3% |
46.8% |
75,000
|
264,288
|
52 |
Kansas City MO-KS |
24.3% |
85.8% |
265,000
|
935,290
|
52 |
Oklahoma City OK |
57.8% |
71.6% |
370,000
|
458,411
|
55 |
El Paso TX-NM |
35.6% |
70.2% |
160,000
|
315,680
|
55 |
Pittsburgh PA |
3.6% |
40.9% |
65,000
|
740,998
|
55 |
Salem OR |
15.6% |
76.2% |
25,000
|
121,905
|
58 |
Eugene-Springfield OR |
13.2% |
65.8% |
25,000
|
125,043
|
58 |
Rochester NY |
-3.1% |
92.6% |
(20,000) |
592,628
|
58 |
Spokane WA |
20.0% |
44.8% |
55,000
|
123,311
|
61 |
Bakersfield CA |
63.0% |
96.0% |
145,000
|
220,914
|
61 |
Beaumont TX |
21.7% |
45.6% |
25,000
|
52,405
|
61 |
Boulder CO |
37.5% |
82.7% |
30,000
|
66,182
|
61 |
Laredo TX |
73.7% |
206.3% |
70,000
|
196,013
|
65 |
Brownsville TX |
61.1% |
87.5% |
55,000
|
78,750
|
65 |
Buffalo-Niagara Falls
NY |
0.0% |
33.5% |
0 |
359,651
|
67 |
Albany-Schenectady-Troy
NY |
0.0% |
76.6% |
0 |
382,796
|
67 |
Corpus Christi TX |
24.0% |
60.2% |
60,000
|
150,472
|
|
|
|
|
|
|
|
ALL |
21.5% |
69.5% |
21,900,000
|
70,644,075
|
1. The TRI Ranking is based on
TTI’s Travel Rate Index. Where numbers are repeated, those Metro Areas had identical
Travel Rate Indices.
2. The term ‘Metro Areas’ refers
to Urbanized Areas which the U.S. Census Bureau defines as developed land with a density
of greater than 1,000 persons per square mile.
Back to Table of Contents
The Surface Transportation Policy Project is a nationwide network of more than 800
organizations, including planners, community development organizations, and advocacy groups,
devoted to improving the nation’s transportation system.
|
STPP
