01044614

Component

Household travel surveys provide demographic and travel behavior details that inform the transportation planning process in general and regional travel demand modeling in particular. They are typically conducted about once every 10 years, based largely on the availability of funding. These surveys document details such as mode of travel, time of day that travel is taking place, and the reasons for travel. The data are used to generate trip rates, build origin-destination tables, and update other assumptions used in the development of a regional travel demand model. They also help to inform policy decisions and prioritize infrastructure investments. Since the late 1970s, most household travel surveys in the US have been conducted using a combination of telephone and mail. Households are randomly sampled, contacted about participating in the study, and, if amenable, are provided with travel logs or diaries for household members to use to document their travel for a specific time period, most often 24-hours. They are either recontacted by telephone to retrieve their travel information or asked to mail these logs back to a central location for processing. The final data sets provide detailed travel behavior information for the region. Despite the importance of this data in planning for the region’s mobility needs and addressing critical transportation-related questions, not all sampled households participate in household travel surveys. Some refuse to participate because of the intrusiveness or time associated with the task of recording all travel for the 24-hour period or because they feel disenfranchised. These refusals are sometimes direct (“don’t call me again!”) and sometimes indirect (they don’t answer their phones). A second group of respondents might be interested in responding but are not home when the telephone interviewers attempt to contact them. A third respondent type includes those without telephones or with cellular-only service, who are not included in a random telephone sample so they are not called at all. All these households travel in the region and contribute to the congestion and other problems to be addressed in the planning process. “Non-response” is a term typically used to refer to the phenomenon that not all sampled households opt to participate in a survey. It is typically measured through comparing the demographics of participating households to the study area population (typically using census data). While slight variations between the population and sample are to be expected, certain sub-population groups tend to be consistently under-represented in the sample. Prior research has shown these groups to include one-person/one-worker households, larger households, lower income households, and minority households. The purpose of this paper is to summarize the population subgroups commonly under-represented in travel surveys, focusing primarily on studies in small and medium-sized communities. A synthesis of the non-response findings from those studies is presented and categorized. For each group, specific design and procedural recommendations effective in other studies are presented. This is followed by a case study of how a transportation planner can use census data to pre-identify potential non-responders in a given region, and how to select methods or processes to mitigate non-response in that region’s travel survey. The important consideration is that these improvements can be built into the design at the start of the study, thus avoiding costly survey corrections while enriching the representativeness of the final data set in an efficient manner. The result is a step-by-step plan for identifying potential non-respondents up front and ensuring that the travel survey design incorporates measures to attract and maintain these groups in the final data set.

01044603

English

11p

2006

10th National Conference on Transportation Planning for Small and Medium-Sized Communities

CD-ROM

References (5) ; Tables (4)

Census; Households; Medium sized cities; Small cities; Transportation planning; Travel surveys

Nonresponse (Surveys)

Data and Information Technology; Highways; Planning and Forecasting; Society; I72: Traffic and Transport Planning

TRIS, TRB

Mar 23 2007 12:03PM

• 1995-2004 CARTS Pedestrian/Bicyclist Crash Analysis
• A Pavement Management System for County Roads in the State of Alabama
• Application of an Internet-Based Travel Survey in a Medium-Sized Community
• Applying Value Methodology to Metropolitan Transportation Planning
• Better, Stronger Faster; How Oblique Aerial Imagery Is Changing the Face of Transportation Planning
• Bozeman Bicycle Network Plan
• Comparison and Evaluation of Simplified Transportation Project Selection and Prioritization Methodologies for Use by Small and Medium Sized Planning Agencies
• Developing a Consistent, Flexible, and Defensible Methodology for State and Regional Transportation Planning
• Development of Travel Demand Modeling Tools for Small Area Planning Purposes
• Discrete Event Simulation of Forecasted Non-Urban Freight Movement
• Evaluating the Relative Safety of Access Management Treatments in Micro-Simulation
• Getting Innovative Traffic Forecasting Model Networks "In Shape" Quickly Using GIS Datasets
• Highway Ranking Model
• Implementation of a Public Transportation System in Casper, Wyoming
• Importance of Modeling Ozone Formation Attributable to Rural Interstate Traffic
• Innovative Financing at the Local Level: Project Funding for a Regional Transportation Agency
• Integrating Access Management into Local Transportation Planning
• La Entrada al Pacifico: Viability and Potential Impacts on the Odessa-Midland, Texas Area and Other Small Communities
• Local Road Safety Audits: A New Approach to an Old Problem
• Microsimulation for Transportation Planning for Small Communities
• New Approach for Updating Highway Functional Classifications
• PlanCheyenne - Co-Planning for MPOs
• Planning Analysis Toolbox for Small Urban Areas in North Carolina
• Potential Use of GPS Data for Calibrating Travel Demand Models
• Safe Routes to School in Superior, WI and Duluth, MN
• Safety Conscious Planning for Small and Medium Size Urban Areas
• Six Hints for Better Public Process
• Strategic Transportation, Environmental Planning Process for Urbanizing Places (STEP UP)
• Successful Use of Public Involvement Tools - Johns Pass Bridge Project
• Supporting Transportation Planning in Small MPOs Through Partnerships and Innovative Methods
• The Bridge Between NEPA and Corridor Studies: The Story of Northern Bridge Corridor Study
• US-280 Access Management - Managing Small Town Economics
• Using Simplified Regression Analysis in Financial Planning for an MTP, or Seeing the Forest for the Trees
• Web-Based Delivery of Geospatial and Transportation Data for a Rural Intelligent Transportation Systems Project
• When Big Projects Come to Smaller Places: The Communication Challenge
• Which Came First? The SR 386 Area Study