Which methods of travel surveys provide more representative data?

Image source «Photobank Lori»
Development of integrated transport infrastructure programs, integrated city mobility and public transport plans involves studies of population mobility in the region. Traffic data can be obtained using automated machine vision systems or social polls.

The main purpose of polls is to get answers to the following questions:
  • How often do you travel during a day?
  • Which mode of transport do you use?
  • At what time during a day do you travel?
  • What are your destinations?

To obtain representative data, over 3 – 5 thousand questionnaires need to be collected and checked. Unfortunately, many respondents give illogical or even contradictory answers that may lead to wrong conclusions.
In our studies we use different survey formats. Below are the advantages and disadvantages of each of them:
  • Street interviews in public attraction places at different time of a day
Advantages: wide coverage and relatively low costs.
Disadvantages: difficult to check response quality and their logic.

  • Telephone interviews by means of phone calls using residents’ database
Advantages: high representativeness of data collected and availability of call records allowing to check response quality.
Disadvantages: high costs and low response percentage (5%-10%).

  • Web interviews, an up-to-date survey method through questionnaires on social media and urban administration websites.
Advantages: quick and inexpensive method.
Disadvantages: need for checking response quality.

We know that many experts have some concerns about the Internet surveys as they believe that the data obtained is not representative because of young age of respondents. However, our experience shows that most respondents are 25 - 45 years old, i.e. they represent the most economically active population frequently using the transport infrastructure.
The disputes about which of the above methods provides the most reliable data will never stop as any expert relies on their personal experience.

To our professional opinion, the most advantageous solution is to use combination of interviewing methods considering a region’s specifics and project goals.