Walls, Nelson, Safirova
Telecommuting and Environmental Policy
telecommuters made 73% fewer morning-peak departures after they began telecommuting and 54%
fewer afternoon-peak departures.
The reduction in number of daily trips translates into a reduction in VMT as well. The average
distances traveled per day by those employees who signed up for telecommuting dropped from 53.7
miles to 13.2 miles on telecommuting days. Compared to non-telecommuters, telecommuters are found
to drive more miles per day, on average, when they are not telecommuting - 56 versus 45 miles. This is
consistent with the findings in many other studies that suggest that people with longer commutes tend to
be the ones who participate in telecommuting programs.
Finally, the Kitamura et al. study also looked at the mode choice of telecommuters and non-
telecommuters. The percentage of total trips made per day that are car trips increases for the
telecommuting employees once they begin telecommuting but holds the same over time for the control
group - telecommuting employees’ share of daily trips made by car rises from 81% to 91% when they
start telecommuting.
Koenig, Henderson, and Mokhtarian (1996) look at home-based telecommuters who
participated in the State of California Telecommuting Pilot Project in the early 1990s. All individuals in
the sample worked for the state government and filled out travel diaries before and one year after they
began telecommuting. The study analyzed 40 people who chose to telecommute at home and 58 who
didn’t telecommute at all - i.e., a control group. The authors find that the people who telecommuted
reduced the average number of daily vehicle-trips they took by 27% and reduced average VMT by 77%.
Using California’s EMFAC7 emissions model, the authors calculate that these reductions in driving
resulted in substantial emissions reductions: 48% in total organic gases, 64% in carbon monoxide, 69%
in NOx, and 78% in particulate matter. Comparing the telecommuters to the control group, the authors
find that telecommuters, prior to joining the telecommuting program, averaged higher total VMT than
non-telecommuters. This result appears to be due to higher non-commute VMT for this group, as
telecommuters reported lower commute VMT than non-telecommuters. Most studies find that
telecommuters have longer average commutes thus the participants in this study appear to differ from
those in other studies.
Mokhtarian and Varma (1998) use data from another California telecommuting program, the
Neighborhood Telecenters Project, which focused on the effectiveness of telework centers in reducing
VMT and emissions. The Project established 15 centers and, as in the previous study, participants and a
control group of nonparticipants filled out travel diaries, both before and after the telecommuting
program began. For this analysis, however, the authors found that the sample size quickly became too
small if they tried to analyze both groups before and after, thus the study focuses only on the telecenter
users and compares travel on days on which they use the center to days on which they do their regular
commute to work. The final sample included 72 people. They find that total VMT is 53% lower on
telecommuting days than on non-telecommuting days, but the number of trips increased. This is
because people apparently drive home for lunch from the telecenter. The authors use the EMFAC7
emissions model and find that emissions on telecommuting days are lower than those on non-
telecommuting days by 15% (ROG), 21.5% (CO), 35% (NOx), and 51.5% (PM).
Henderson and Mokhtarian (1996) also focus on telecenters. Their data are from the Puget
Sound Telecommuting Demonstration Project sponsored by the Washington State Energy Office in
1990-91. The sample in this study includes 71 telecommuters - 8 center-based and 63 home-based -
and 33 non-telecommuters. The individuals worked for both government and private companies and as
in the other studies, extensive travel diaries were kept on all commute and non-commute travel.
Henderson and Mokhtarian find that total VMT for telecenter users dropped by nearly 54% on days on
which they used the telecenters compared with non-telecenter days. By comparison, home-based
telecommuters reduced their VMT by 66.5% by working at home. The telecenter users had the highest
total daily VMT of the three groups, prior to the start of the telecommuting program, 91% greater than
the control group. Home-based telecommuters had daily VMT 54% greater than the control group.
Again in this study, emissions reductions are calculated. All pollutants are reduced, but NOx and PM
are reduced more than total organic gases and CO since they are more directly linked to miles traveled.