The Work Trip in the Context of Daily Travel

Report
The Work Trip
in the Context of Daily Travel
Census Data for Transportation
Planning Conference,
May 2005
Nancy McGuckin, Travel Behavior Analyst
Nanda Srinivasan, Cambridge Systematics
Q: How Important is the Work Trip to
our Understanding of Daily Travel?

Overall, one out of five trips and one out of four miles are traveled in
commutes.

For workers, over 40 percent of miles and minutes of travel on
weekdays is spent in commutes.

Commuting continues to predominate weekdays and peak periods,
(nearly 72 percent of workers depart between 5:00 and 9:00 am)
contributing to congestion.

The proportion of direct (non-stop) trips to work continues to decline.
In 2001, over half of commuters made non-work trips during their
commutes.
Work Trips Have Declined
as a Proportion of All Trips
Work Travel as a Proportion of All Travel
40%
30%
20%
10%
0%
1969
Person Trips
1977
1983
Person Miles of Travel
1990
Vehicle Trips
1995
2001*
Vehciles Miles of Travel
Other Types of Trips are Growing
Faster than Work Trips
Added Annual Trips per Person by Purpose 1990 - 2001
50
45
Added Annual Trips per Person
40
35
30
25
20
15
10
5
0
To/From Work
Family & Pers Errands
Shopping
Soc/Rec (inc Visit)
Workers Account for
A LOT of Daily Travel
Comparison of Travel by Workers and All Others 16+
Workers
All Others 16+
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Population
Tripmakers
Person Trips
Vehicle Trips
PMT
VMT
Sum of All Travel
Time
Workers do More
Than Commuting
Proportion of Work- and Non-Work Trips Made by
Weekday Workers
Work Trips
Non-Work
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Person Trips
Vehicle Trips
PMT
VMT
PMT IN POV
SUM OF ALL TT
Even When They Have
Long Commutes
Weekday Minutes of Travel
Work Tours
NonWork
140
120
100
80
60
40
20
0
<15 mins
15-29 mins
30-44 mins
Commute Time Categories
45+ mins
Less Than Half of Commuters
Make Direct Trips to Work
1990
2001
2
1.8
Mean HBW Trips
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Sun
Mon
Tue
Wed
Thu
Fri
Sat
The Mountain of Growth in
is in Non-Work Travel
Difference in Number of Trips by Time of Day, 1990 - 2001
2.50E+10
HBW
HBShop
HBSoc
HBO
NHB
2.00E+10
1.50E+10
1.00E+10
5.00E+09
0.00E+00
Mid-6am
-5.00E+09
6 - 9am
9-noon
noon-3pm
3 - 6pm
6 - 9pm
9 - Mid
Using Work Tours
Captures More Realistic Picture
HBW Trips
Work Tours
Mean HBW or Work Tours/Worker
2.5
2
1.5
1
0.5
0
Sun
Mon
Tue
Wed
Thu
Fri
Sat
what
Complex Work Tours Look Like
We Think We Know
Pick-up Present for
Boss’ Birthday
Drop Child At Daycare
Home
Work
Pick Child up at Daycare
Pick-up Groceries for Dinner
But, Do We Really?
,
Home
Trip 7 – Shop to Home
Trip 6 – Shop to Shop
Trip 8 – Home to
Pick-up Child
Trip 5 – Work to Shop
Trip 1 – Home to Work
Trip 2 – Drop Child at Camp
Trip 3 - Shop
Trip 4 – Back to Work
Work
Real Life is Messy
360010129.00
360010130.00
360010135.03
Trip 5: Store to Store
360010138.02
360010135 .02
360010135.06
Trip 6: Store to Home
Trip 4: Work to Store
360010138.01
HOME
360010137.03
WORK
Trip 7: Home
to D ay Camp
Trip 1: To Work
Trip 2: Work to Childs D ay Camp
Trip 4: Store to Work
360010139.02
360010137.07
36 0010136.01
Trip 3: Day Camp to Store 360010139.01
360010004.01
360010146.07
360010140.01
360010137.05
360010137.06
360010140.02
36 00 10 00 4.04
360010146.10
360010136.02
360010146 .08
360010003.00
36 00 10 14 6.09
36 00 10 004.03
360010018.02
360010007.00
360010002.00 36 00 10 00 1.00
But, Is a Good Household Travel Survey
Good Enough?
Unique pairs of Worker Residence and Work Location Tracts, n=445
Not for Small-Area Geographic
Coverage
Unique pairs of worker residence and workplace locations, n=8,953
HTS Overstates Some Potential Flows
and Misses Others Completely
Total Workers Trips into Albany=106,058)
Legend
NHTS Flows
DAILY_WORK
31 - 200
201 - 400
401 - 600
601 - 800
801 - 1800
Journey-to-Work Flows
More Reasonable
Total Work Flows into Albany=218,715
In major characteristics,
Census data matches ‘real’ commutes
How usual is a ‘Usual’ day:

Mode of travel matched for over 70 percent of commutes

Travel time matched better for workers with short
commutes (70 percent) than with long travel times (30-50
percent)

Departure time also very, very similar
Best of All Possible Worlds:
Work flows at small-area geography
AND
Descriptions of the real-life travel
behavior from a household travel survey
Conclusion

What makes the JTW invaluable?
It is the work trip data collected in conjunction with the
residence and workplace locations with such precise
geographic detail.

Transportation planners can evaluate potential
work travel at small-area geography
While using other data sources to expand their
understanding of the work trip to the whole of daily
travel.
Conclusion
The journey-to-work data are still relevant and
needed for small-area planning, and are widely
used by transportation planners and analysts.
There is a particular need for these data in areas that
do not have a local, current household travel
survey.
Looking Forward

ACS will result in fewer flows, and fewer OD
pairs

Planners hope that they can learn to make these
data as useful and relevant as the CTPP

This conference is a good overview of issues
(e.g. confidentiality and thresholds, sample sizes, uses in modeling)

Guidebook will be vital in helping local planners
We Need to Connect
Workplace Data to Daily Trip-making

Journey-to-work flows are not trips

LED promises comprehensive employment
summaries, but not trip attraction rates

For instance, 15 employees at a small fast-food
place can attract 1500 daily trips

We need to know the 1500, not just the 15

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