Walls, Nelson, Safirova
Telecommuting and Environmental Policy
dramatically reduced the emission rates of new cars over the past 20 years. As a result, the emissions
savings from averting a vehicle trip of a new car are much lower than the savings of averting a trip using
an old car.
Table 9 begins by showing the average one-way distances commuted from home to office. The
average one-way distance traveled by employees in the ecommute program is just over 22 miles. Not
surprisingly, Los Angeles has the highest average commute length at nearly 34 miles; Denver’s is the
lowest at approximately 20 miles. In each of the cities, however, the range is wide. Some employees
report that they commute only a mile each way, while the longest one-way commute is 146 miles.17 The
mean is greater than the median in each of the cities because of these few participants with very long
commutes.
The average one-way distance of 22 miles appears somewhat high. In a report on telecommuting
and emissions trading and the potential of the ecommute program by the National Environmental Policy
Institute (NEPI, 2000), estimates of average distance to and from work, net of miles traveled for non-
work trips during the day, were given for each of the five cities. These averages are as follows: 19
miles (DC), 15 miles (Denver), 27.5 (Houston), 16.5 (Los Angeles), and 12.5 (Philadelphia). With the
exception of Houston, these averages are all below the averages in the first column of Table 9.
Table 9. Distribution of One-Way Distance Commuted by Participants in the ecommute Program,
by City
as of March 1, 2004
(in miles)
|
Mean |
Median |
Std. Dev. |
Minimum |
Maximum | |
|
Washington, DC |
24.1 |
20.0 |
21.2 |
3 |
115 |
|
Denver |
19.7 |
15.0 |
14.7 |
1 |
85 |
|
Houston |
22.3 |
16.5 |
19.5 |
1 |
146 |
|
Los Angeles |
33.6 |
30.0 |
20.6 |
5 |
80 |
|
Philadelphia |
25.3 |
20.0 |
19.2 |
1 |
100 |
|
ALL CITIES |
22.4 |
17.0 |
17.9 |
1 |
146 |
An analysis of a telecommuting survey done by the Southern California Association of
Governments (SCAG) shows that the average commuting distance of a teleworker is 21 miles in Los
Angeles and the surrounding region. The SCAG number is useful as a comparison since it is an average
only of people who telecommute and not the general population. The Houston figure in Table 14 is
reasonably close to the NEPI estimate: the average one-way distance for participants in the ecommute
program is 22 miles, while the NEPI report estimates a distance of 27.5 miles. The medians reported in
Table 9 are actually closer to the averages reported by NEPI, at least the median distances in Denver
and Washington, DC, match up well. Again, the relatively few participants in the ecommute program
who live a long way from their workplace appear to be driving up the means in Table 9.
Tables 10 and 11 show the distribution of vehicle types and ages among the 535 employees in
the ecommute program. Table 10 shows that most employees, 67%, own light-duty gasoline vehicles.
The next highest percentage is mid-size trucks at nearly 18%, followed by full-size trucks (>8,500
pounds) at 7.5%. Table 11 indicates that most of the employees in the ecommute program own
relatively new vehicles. Only 5.6% of the vehicles in use by ecommuters are pre-1990 vehicles. Fully
41%, on the other hand, are model year 2000 or newer. The average vehicle is 5.4-years-old.18
17 The distances were missing or erroneously reported as zero for a few employees in the dataset. When we had
the zip codes available, which we did in most cases, we looked up on the Internet distances between zip codes.
18 This is actually an overestimate of vehicle age. We calculated this figure by subtracting the vehicle model year
for each employee from 2003 and then computing the average age. However, some participants were in the
program prior to 2003 and dropped out (or stopped reporting), thus their vehicles were newer in those years than
they were in 2003. We do not adjust for this.
18