1. Income and Vehicle Ownership
a. Income and Vehicle Ownership
The argument is often made but not always listened to: low income
households will own fewer vehicles, and thus less parking is
needed. Well, all data, including Bay Area specific data, holds that
vehicle ownership is significantly lower among lower income households.
Not only is there a statistical relationship, but transportation research has
identified as the most significant factor in determining the amounts of vehicles
owned by households. In a review of 17 studies since 1966 on vehicle ownership,
the most common variable (in 15 of 17 studies) found to have a
significant association with vehicle ownership was household income.1
In 1990, the average number of vehicles per household was 1.76 in the
Bay Area. However, households earning
between 48 and 60 percent of the median income owned on average only 1.30
vehicles, 26% below the region wide mean. Below
is a chart and table with the relationship between income and vehicle ownership
in the region. After the chart is a table of the data. The data is
also available in Excel format.
|
Observation |
Lower income
households own fewer vehicles per household than average. |
|
|
|
|
Implication |
Minimum parking
requirements could be decreased for housing that will permanently serve
lower income households. |
| *
|
Income
(in 1990)
|
Inflation
Adjusted
1990
Income
in
2000 Dollars
(in
thousands)
|
Income
as
% of
Median
Income
|
Midpoint
of
Median
Income
Range
|
Average
Vehicles
per
Household
|
Percent
of
Households
w/
0 Vehicles
|
Number
of Households |
Percent
of
All
Households
|
| |
|
|
|
|
|
|
|
|
| |
less
than $5000 |
less
than $6.8 |
0%
-12% |
6% |
0.85 |
37.7% |
71,963 |
3.2% |
| |
$5,000
- $9,999 |
$6.8
- $13.6 |
12%
- 24% |
18% |
0.68 |
46.9% |
138,415 |
6.1% |
| |
$10,000
- $14,999 |
$13.6
- $20.5 |
24%
- 36% |
30% |
0.98 |
27.7% |
128,457 |
5.7% |
| |
$15,000
- $19,999 |
$20.5
- $27.3 |
36%
- 48% |
42% |
1.16 |
18.7% |
133,856 |
5.9% |
| |
$20,000
- $24,999 |
$27.3
- $34.1 |
48%
- 60% |
54% |
1.30 |
13.2% |
148,345 |
6.6% |
| |
$25,000
- $34,999 |
$34.1
- $47.7 |
60%
- 84% |
72% |
1.49 |
8.8% |
305,727 |
13.6% |
| |
$35,000
- $49,999 |
$47.7
- $68.2 |
84%
- 120% |
102% |
1.81 |
4.4% |
417,309 |
18.5% |
| |
$50,000
- $74,999 |
$68.2
- $102.3 |
120%
- 180% |
150% |
2.18 |
2.2% |
478,515 |
21.3% |
| |
$75,000
- $99,999 |
$102.3
- $136.4 |
180%
- 240% |
210% |
2.45 |
1.3% |
223,337 |
9.9% |
| |
$100,000
or more |
$136.4
or more |
>
240% |
240%+ |
2.56 |
1.0% |
205,051 |
9.1% |
| |
|
|
|
|
|
|
|
|
| |
All
Households |
|
|
|
1.76 |
10.3% |
2,250,975 |
100.0% |
| |
|
|
|
|
|
|
|
|
Excel
Spreadsheet - Income vs. Vehicle Ownership
How
to Use This Information:
The
charts and data on this page (available in Excel spreadsheets) are
specific to the Bay Area and can be used in discussions with communities and
local governments/planning departments.
- You
can "right-click" in your browser on the chart, and
- Click
"Save Image As" to save the chart as a GIF file which you can use
for applications and presenations.
Otherwise,
download the Excel files which has both the chart and the table. Use the
appropriate income level as a fact in your applications and analyses. For example, if
your project targets households at 35% of AMI, you may want to point out that households earning between 24% and 36% of the regional median income averaged
0.98 vehicles, 44% below the region wide mean of 1.76.
Next:
b.
Household
Size, Income and Vehicle Ownership
Sources:
Vehicle ownership data compiled from
MTC compilations of 1990 US Census Data Metropolitan Transportation
Commission. 1995. San Francisco Bay Area Detailed Household Characteristics. Availabe at
http://www.mtc.ca.gov/datamart/census.htm
(Visited March 2001).
Inflation of 1990 Income to 2000
dollars, based on an inflation factor of 1.364.
Inflation index is calculated for the Bay Area and is
available from ABAG. Available at: http://www.abag.ca.gov/abag/overview/datacenter/retail/cpi.html
(Visited March 2001)
Ewing, Reid and Shi-Chiang Li. 1998.
A Vehicle Ownership Model for FSUTMS. Washington, D.C.: National Research
Council, Transportation Research Board.
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