2001 national household travel survey kentucky add-on

2001National Household Travel Survey

Kentucky Add-on

Ben Pierce

Presentation By

Acknowledgements

MORPACE, International

FHWA, Office of Highway Policy

Information

Kentucky Traffic Model Users Group: Travel Survey Workshop

NHTS

Presentation Outline

What is the NHTS? What is the NHTS Add-on Program? Kentucky’s Involvement Overview of Survey Methodology Review of Collected Data Summary of Participation Selected Results in Kentucky


NHTS

What is the NHTS?

Travel survey that collects information on travel from a national sample of the civilian, non-institutionalized population of the United States

Conducted roughly every five years since 1969, last conducted in 1995

Traditionally collected travel information for one day of travel; in 2001 also collected information on long-distance travel (prior 28 days)

Data are used to produce national estimates of travel and investigate topics in transportation safety, congestion, mobility of various population groups, the relationship of personal travel to economic productivity, the impact of travel on the human and natural environment, etc.


NHTS

What is the NHTS Add-on Program?

~26,000 households included in the national sample

National sample designed for national estimates – not enough for reliable state and local estimates

FHWA offered states and local municipalities the opportunity to purchase additional samples specific to their area

In 2001, additional samples were purchased by nine state and local municipalities, adding an additional ~66,000 households

These additional samples are referred to as NHTS Add-ons


NHTS

Kentucky’s Involvement

Kentucky participated as a 2001 NHTS Add-on Purchasing 1,100 households in Kentucky

CountyNumber ofPurchased

Households

Number ofCompleted

Households

Carter 150 150

Edmonson 150 165

Pulaski 400 423

Scott 400 416

Total 1,100 1,154


NHTS

Overview of Survey Methods

Computer Assisted Telephone Interview (CATI)

Samples (households) are selected based upon telephone numbers using list-assisted, random digit dialing methods

Two stage survey– Household interview

– Person-level interview (Extended Interview)


NHTS

Overview of Survey Methods (cont.)

Pre-Contact Letter

Household CATI

Interview

TravelDiaries

Telephone Reminder

Calls

Extended CATI

Interviews

Signed by Terri Giltner,Exec. Dir.Office of Public Affairs, KYTC

$2 incentive

First Class mail

Up to 19 calls

Household characteristics

Household demographics

Respondent 18

Diaries + Memory Aids

$2 per person incentive

Priority Mail

Travel Day is 10-16 days after Household Interview

Day before Travel Day

Message left on answering machine

3 busy signals before no-contact

Within 6 days after Travel Day

Personal travel characteristics

Trip information

Proxy reporting allowed


NHTS

Overview of Survey Methods (cont.)

Things to Note: NHTS employs a “memory jogger” style

diary, and is a trip-based survey Information on trips is collected by first

“rostering” all trips for an individual, then going back and asking detailed information for each trip

Trips are 1-way; origin-to-destination Proxies are permitted, but only under certain

conditions


NHTS

Please remember, a trip is whenever you go from one address to another.Have this diary by the phone when the interviewer calls. You do not need to mail it back to us. Thanks!

NATIONAL HOUSEHOLD TRAVEL SURVEY

TRAVEL DIARYAt the beginning of my travel day (4:00 a.m.) I was: Home Some other place

What was the LOCATION? What TIME did youstart and end each trip?

WHEREdid you go?

(Name of place)

ADDRESS INTERSECTIONTYPE OF PLACE OR

BUSINESS Started at: Arrived at:

HOWdid you travel?

How FARwas it?

(blocks or miles)

EXAMPLE:West Park

2900 Main St.Southfield, MI 48031 Main St. & Evergreen Rd. Shopping Mall 2:00 pm 2:55 pm Walk, bus, walk 6 miles

1.

ABC123 Polk St.Chicago, I L 60602

Polk St. & State St. Offi ce Products 7:35 a.m. 8:43 a.m. Car, Subway, Walk 12 miles

2.

New City Diner1220 Wabash St.Chicago, I L 60602

9th St. & Wabash St. Restaurant 12:04 p.m. 12:16 p.m. Walk 2 blocks

3.

ABC123 Polk St.Chicago, I L 60602

Polk St. & State St. Offi ce Products 12:58 p.m. 1:10 p.m. Walk 2 blocks

4.

Fast Gas3437 Stone Park Rd.Melrose Park, I L 60571

Stone Park Rd. & Chicago Ave. Gas Station 5:50 p.m. 6:35 p.m. Walk, Subway, Car 11 miles

5.

Super Deal3560 Stone Park Rd.Melrose Park, I L 60571

Stone Park Rd. & 35th St. Grocery Store 6:42 p.m. 6:48 p.m. Car 1 block

6.

Happy Kids1832 Wolf Rd.Northlake, I L 60575

Wolf Rd. & Franklin Ave. Daycare Center 7:05 p.m. 7:09 p.m. Car 4 blocks

7.

Home279 Fair Oaks Rd.South Plainfield, I L 60521

Fair Oaks Rd. & Ridge Rd. Residence 7:14 p.m. 7:22 p.m. Car 1 mile

8.

9.

10.


NHTS

Three Methodological Differences from NHTS National Methodology1. National Sample used $5 incentive vs. $2 in

Kentucky Add-on

2. National Sample included questions on long-distance travel, Kentucky Add-on did not

3. Definition of a “completed” household differed:

National Sample = At least 50% of householdmembers aged 18 years or older needed tocomplete the extended (person-level) interview

Kentucky Add-on = All members of thehousehold needed to complete an extended(person-level) interview


NHTS

Data Collected

FOR EACH HOUSEHOLD:Number of peopleNumber of driversNumber of workersNumber of vehiclesIncomeHousing typeOwned or rentedNumber of cell phonesNumber of other phonesRace of reference personHispanic status of reference personTract & block group characteristic

FOR EACH PERSON:AgeGenderRelation to reference personDriver statusWorker status/Primary activityInternet useTravel disabilityEffect of disability on mobilityHighest grade completedImmigrant statusViews on transportationAnnual miles drivenIncidence of public transit use in past two monthsIncidence of walk and bike trips in past week


NHTS

Data Collected (cont.)

FOR EACH WORKER:Full or part‑time workMore than one jobOccupationWorkplace locationUsual distance to workUsual travel time to workDrive alone or carpoolWork from homeIf commercial driver, amount of commercial travel

FOR EACH VEHICLE:MakeModelAge (year)

DAILY TRAVEL DATA:Origin & destination address (geocoded to Latitudes and Longitudes)Time trip started and endedDistanceMeans of transportationVehicle typeIf household vehicle, which oneIf transit, wait timeIf transit, access and egress modesDetailed purposeNumber of others on tripSpecific household membersNumber not household membersWho droveMost recent trip, for non‑travelers (date)


NHTS

Data Collected (cont.): Geocoding ResultsGeocoding Level Number of Locations Percentage

Households

Address Level 1,126 97.6%

Closest Intersection 20 1.7%

Zip Code Centroid 5 0.4%

Non-Geocodable 3 0.3%

Work Locations

Address Level 938 82.6%




Trip Destinations

Address Level 7,856 80.4%





NHTS

Summary of Participation

50% of eligible households provided household-level information. Household response rate ~40%

Detailed travel information collected from ~53% of households that completed the household interview and agreed to provide travel information

~40% of all attempted person-level interviews were completed

The overall, person-level response rate for the study ~18%

– Scott County Telephone Issues– Person-level RR lower in Pulaski and Scott– HH level issues were refusals and no-contacts (Scott)– Person-level issues were no-contact cases


NHTS

Results: Summary of Participating Households

Summary of Participating Households

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

40.0%

45.0%

50.0%

1 2 3 4 0 1 2 3+ < $20k $20k -$39k

$40k-$59k

$60k>

Per

cen

t o

f H

ou

seh

old

s

Weighted Unweighted 2000 Census

HH Size No. of HH Veh. HH Income


NHTS

Note on Survey Weights

The NHTS utilized a complex sampling scheme – i.e. this isn’t a simple random sample!

Survey weights were developed for each type of data (household, person, vehicle, trip-level)– Account for complex survey design– Differences in non-response– Post-stratification

Survey weights should always be used when calculating standard errors or measures of precision (e.g., confidence intervals)


NHTS

Results: Miles of Travel

Vehicle Miles of Travel

3,435,945 or

1,254,120,088 Annualized

Miles Per Vehicle

32.1 or

11,702 Annually

Person Miles of Travel

5,329,575 or

1,945,294,783 Annualized

Miles Per Person

41.7 or

15,220 Annually


NHTS

Results: Trips

Trips per Household per Day

5.7 Vehicle Trips/HH

9.1 Person Trips/HH

Total Number of Reported Trips

Person Trips Vehicle Trips

453,554 285,913

165,547,299 Annually 104,358,225 Annually

Trips per Person per Day

2.2 Vehicle Trips/person

3.5 Person Trips/person


NHTS

Results: Percentage of Trips by Day of the Week

Percentage of Trips by Day of Week

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

Sunday Monday Tuesday Wednesday Thursday Friday Saturday

Per

cen

t o

f T

ota

l Tri

ps

Vehicle Person

HH Size No. of HH Veh.


NHTS

Results: Percentage of Tripsby Trip Purpose

Percentage of Trips by Trip Purpose

0% 5% 10% 15% 20% 25% 30% 35% 40%

Home

Work

School/Religious Activity

Medical/Dental Services

Shopping/Errands

Social/Recreational

Family Personal Business/Obligations

Transport Someone

Meals

Other

Don’t Know

Percent of Total Trips


NHTS

Results

Many More Results…..

2001 national household travel survey kentucky add-on

Documents

travel survey workshopwhat

day of travel

travel daymessage

impact of travel

collected travel information

national estimates of

kentucky page

detailed information