Travel Surveys

Texas urban area comprehensive travel surveys may include any or all of the following surveys:

Data from these surveys serve as inputs to the travel demand models to ensure that the travel models adequately reflect regional travel behavior.

Household Survey

In households selected at random throughout the urban area for survey, interviewers ask people who agree to participate to record in a diary the activities and travel by each person during a 24-hour period. For each trip, interviewers ask participants to record the time, activity, place the trip began and ended, mode of travel, number of passengers, purpose of the trip, and other descriptive information. In addition to the data on travel, interviewers record characteristics of the household such as number and age of persons in the household, number of household members employed, household income, and number of vehicles available. TPP uses data from the household survey to develop trip production rates for the urban area.

Workplace Survey

A workplace survey collects information on travel at the destination end of trips. This type of survey consists of two primary parts: one part designed to collect information on the size and characteristics of the workplace in combination with traffic counts, and one designed to collect travel data on non-employees and employees traveling to/from the workplace during the day. For the workplace survey, TPP cross-classifies employment establishments by employment type (basic, service, retail, or educational), area type, and freestanding or non-freestanding business. Interviews with randomly selected non-employees and employees arriving at the workplace during the survey day ask them to identify trip origin, trip purpose, mode of travel, vehicle occupancy, and arrival/departure times. TPP uses the data collected from the workplace surveys in conjunction with traffic or person counts at the specific workplace to develop attraction rates for basic, service, and retail employment for each area type.

External Station Survey

At each external survey station location, surveyors randomly select vehicles and interview the drivers to determine information on the trip purpose, the trip origin and destination, and the vehicle occupancy. TPP uses this information to estimate the number of trips originating outside the study area and traveling to a point inside the area, the number of trips beginning and ending at a point outside the study area (through trips), and trips originating inside the study area and destined to a point outside the study area.

Commercial Vehicle Survey

In some areas, TxDOT conducts a separate commercial vehicle survey to develop a more comprehensive database of travel patterns, vehicle weights and fuel types for commercial vehicles operating in the urban area. TPP uses information collected from this survey to develop commercial vehicle trip estimates for trip productions. Participating firms provide data for each trip taken during one day’s travel. Information collected includes departure and arrival times, an address for each destination, vehicle types, vehicle weight, and fuel type.

Special Generator Survey

Special generator surveys collect information on travel patterns for employees and visitors at sites that exhibit special trip generating characteristics. Special generators are unique employment sites that generate or attract lesser/greater amounts of traffic than employment sites within the same employment category (i.e. basic, retail, service or educational).

On-Board Public Transit Survey

(performed by MPOs)

An on-board survey of bus passengers collects information on current bus rider characteristics and provides data to develop a representative origin-destination trip table for use in the mode-split element of travel demand models. Data collected include trip origins and destinations, mode of travel to/from bus stop, trip purpose, transit routes taken during trip, ridership frequency, fare paid and method of payment, vehicle availability, household size, and household income. TPP does not perform on-board public transit surveys, but can advise in some capacities. These surveys may or may not be necessary for a specific MPO.