# Presentation: 917659

## A Walk Through TimeChanges in the American Commute

**U.S. Census and the **
**National Household Travel Survey**
**June 2003**
**Nancy McGuckin, Travel Behavior Analyst**
**Nanda Srinivasan, Cambridge Systematics Inc.**

## In the last forty years there’s been:

**Changes in family structure and increase in vehicle availability**
**Changes in the working population**
**Increases in private vehicle use and significant increases in commute time**
**Growth in non-work travel changing the landscape of our peak periods—A trend expected to continue **

## Changing Family Patterns

- In 1960 **61%** of the households had:
- a father working outside the home,
- a homemaker mother, and
- three children

- In 2000 **67%** of households are **not** nuclear family:
- 28 % are married with no children at home
- 26% are living alone
- 13% are other related or unrelated

- U.S. Census

**Notes:**
The family structure has changed dramatically since 1960.  It’s a bit like moving from Ozzie and Harriet to Ozzy Osborne. In 1960, the vast majority of households were families with children. In 2000 families with children account for less than a quarter of all households, surpassed by single person households for the first time in history.  

## More single-person households were added than other types...1990 - 2000

- U.S. Census

## Households are getting smaller with more vehicles...

**Notes:**
For the first time in history, single person households are a greater proportion of U.S. households than nuclear families, which come third after singles, married, and then married with children. 
The number of vehicles per household continues to rise just as the number of people per household continues to fall. And vehicles are being kept longer...the average car on the road is now almost nine years old (compared to 6.6 years old in 1977).    

## Many households have multiple vehicles ...

- U.S. Census

**Notes:**
11.3 million households had no vehicle in 1960, and 10.9 million households in 2000.
BUT with changing HH size, many MORE people in 1960 had no access to a car at home (38 million versus 28 million in 2000). Vehicles per person in 1960 was 0.3 and grew to twice that (0.6 per person) in 2000.

## Even though you can only drive one car at a time, more vehicles add more miles of travel....

**Notes:**
Adding more vehicles than drivers has an effect on the miles of travel. 

## Changing Workforce

- In 1960:
- 38 percent of all women work, but few women with young children go to work
- Majority of families have only one worker

- In 2000:
- 61 percent of women work, including two-thirds of women with children under 6.
- Shift to dual-earner families, higher income households, and one vehicle per worker

- U.S. Census

**Notes:**
The number of workers grew by 2 times since 1960. The most dramatic change in the workforce is the inclusion of women, who flocked to work throughout the 70s and 80s. Much of the growth in household income over the last two decades can be attributed to dual-income households.

## Change in Population, Workers and Drivers 1969 - 2001

- NPTS Data Series

##  Two-thirds of U.S. adults are 	workers (67%),

-  Two-thirds of U.S. adults are 	workers (67%),
-  145 million workers compared to 	71 million non-workers.
-  Each worker travels on average 	12 miles more per day, or
-  1.74 billion more miles a year 	than non-workers;
-  That is 73 percent of total miles.

- 2001 NHTS

## The worker boom is over...Millions of added workers per decade--U.S. Census

**Notes:**
The worker boom is over.  The baby boomers who overflowed the schools and helped the housing boom are headed toward retirement. Some people worry about the lack of workers to support the economy in the coming decades—in 1960 there were five workers for each social security recipient, in 2025 there will be two workers for every SS recipient.  Continued work by baby boomers, rather than traditional retirement, and immigration are a couple of sources to fill workforce needs. 

## More workers and more cars on the road...Millions of Workers commuting by POV—U.S. Census

**Notes:**
In 1960 41 million commuters were in cars.
By 2000 nearly three times that many were commuting in vehicles.

## A Real Shift to Longer Commutes...

- U.S. Census

**Notes:**
Now, I should explain a bit about the three minute increase in travel time from 1990 to 2000. 
In 1990 the census top-coded reported travel time to 99 minutes or more, whereas in 2000 the top code was 240 minutes.  This effects the averages and means, of the overall average of 3.1 minutes of increase since 1990, about 2.1 minutes are considered ‘real’ and one minute a residual of the coding.
However, even a two minute shift in the average is IMMENSE!  The decade from 1980 – 1990 (remember all the added workers?) had only a 40 second increase.

But the 2000 number is closer to reality, and the distributions we see in the data are not effected by the top-coding issue. 

## However, commuting as a proportion of all travel is declining...

- NPTS/NHTS Series

**Notes:**
Trips to and from work have been declining as a portion of overall travel since 1969, when work accounted for over 25 percent of person trips and nearly 35 percent of vehicle miles of travel.  In 2001 work accounted for just under 15 percent of person trips and 28 percent of vehicle miles of travel.

## Since 1990 the average American added more recreation, errands and shopping than work trips.

- NPTS Data Series

**Notes:**
The actual number of work trips per person has grown—work trips per working-age person (16 and over) has increased by nearly 20 work trips per year since 1990.  But trips for other reasons have increased more. 

## Some of these trips have been added in stops on the way home from work (trip chains)

- 1995 NPTS

## Vehicles commutes by time of day...

- NHTS 2001

## All Vehicles in Motion—

- The Changing Peak Period

- NHTS 2001

## Changes in family structure, workforce and vehicle availability primarily effected mode choice in the 1980s
People may have shifted to POV and drive alone to save travel time

**People may have shifted to POV and drive alone to save travel time**

**Notes:**
In summary, the 1980s saw a real shift in mode.  People are trying to get to work with minimum time expenditure...

## In the 1990s travel times have really shown significant increases...how will people respond?
Expect a shift in departure times as workplaces become more flexible and people try to minimize their travel time. 

**Expect a shift in departure times as workplaces become more flexible and people try to minimize their travel time. **

**Notes:**
The 90s saw a significant shifts in travel time. What else can people do to get to work as fast as possible (or is that to get home as fast as possible?)

I expect a shift in departure times, more peak spreading, possibly more work at home, and as service industry grow more non-peak work travel.

## 
Increased travel time to work (Census) may indicate the effects of a better economy, sprawl, congestion, etc.  Further research is necessary at small geography to untangle these issues.

Increased total time in travel may be the effect of added trips for non-work purposes, either on the work trip (trip chaining), weekend and evening trips, or increased trip making by non-workers (especially retired)

**Increased travel time to work (Census) may indicate the effects of a better economy, sprawl, congestion, etc.  Further research is necessary at small geography to untangle these issues.**
**Increased total time in travel may be the effect of added trips for non-work purposes, either on the work trip (trip chaining), weekend and evening trips, or increased trip making by non-workers (especially retired)**

- Americans are Spending More Time in Travel

## The purposes of the growth in travel is changing...

**Increased travel for non-work purposes is discretionary travel, social, recreational, and shopping.**
**What will happen with the coming changes in the workforce (such as retiring baby-boomers) and discretionary travel?**
**Stay Tuned!**