KY 4/22 Module 1a

KY 4/22 Module 1aPurposes of Data Collection

Review of initial handouts

•Travel Survey Manual, TMIP, USDOT andEPA, 1996

•Travel Survey Manual Appendices, includessample RFPs

•Travel Survey Course CD

•TRB Committee on Travel Survey Methods(A1D10) reports page

Main differences between 1996and TODAY

•Greater use of computers for data entry atall stages

•Greater use of GPS

–Future implementation of E911 with GPS incellular phones

•Continuing decline in response rates

•Population sub-groups who rely solely oncellular phones.

Data collection purposes

•Travel Demand Models

•Demographic characteristics not avail fromother data sources

•Trend analysis

•Borrowing data (transferability)?

Data collection purposes

•Travel demand models

–Trip Generation Rates

–Trip Length Frequency Distribution

–Model validation and calibration

–Mode choice models (FTA New Starts)

–Vehicle acquisition models

Demographic Characteristics notalways avail from other sources

•Volume counts, passenger counts do notinclude characteristics such as:

–Vehicle ownership

–Household income

–Household size

Trend Analysis

•Daily weekday person trip rates

•Driver licensing

•VMT

1969-2001 NHTS trends

Annual Miles Per Driver

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Significantly more households in 2001where there are more vehicles than thereare drivers.

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1995

2001

15 million

14.5million

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63 million

64.5million

14million

20 million

1.4million

2.8million

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Source: Patricia Hu, ORNL. Jan 2003

Borrowing Data/Transferability

•Primary data collection can be expensive.Sometimes you need to borrow data.

•NCHRP 365 (NCHRP 187)

•NPTS Transferability Pilot

•“Quick Response”

Maybe you decide that primarydata collection necessary

•Let’s try some now.

Fill out a Travel Diary

•Your assigned travel day is :

Thursday, April 17

•Need a volunteer to tabulate:

–Average # of person trips per day

–Average # of vehicles per driver (inhouseholds)

Constraints to Data Collection

•Three-legged stool

–Quality

–Quantity

–Cost

What’s the hardest part ofprimary data collection?

•What do you think?

What’s the hardest part ofprimary data collection?

•Elaine’s opinion:

–Getting the budget for the project

–Response rates and potential samplebias

–Reporting geographic information