Importance of Origin Destination survey methods
The most important measure for a successful survey is a level of participation which relies on origin destination survey methods. Therefore, reliable assistance of as many respondents as possible is the key to a successful survey. Some of thing which can be done for a respondent friendly survey are:
- Design the questionnaires in a type size that people can read, a clear layout, and understandable questions.
- Keep the questionnaires as short as possible.
Origin Destination survey methods for data collection includes:
- Roadside Interview
- License plate Mail-out surveys
- Telephone survey
- Internet surveys
- Mail surveys
Various Origin Destination survey methods are described below:
a) Roadside Interview
This interview includes directing vehicles into a designated area and asking a series of sort questions. This technique is widely used and has a very high response rate but sometimes implementation is difficult due to disruption of traffic. In this method investment cost is low but requires high labour and personnel requirements. This method has a broad geographical coverage as it includes vehicles from outside the study area also, but implementation can be for limited locations and hence sampling may be biased.
b) License plate Mail-out surveys
The license plate mail-out survey involves recording license plate numbers of vehicles on a selected roadway, tracing vehicle ownership, and mailing a survey to owners. There are different methods for tracing the license plate number: taking a photo/video or manually recording the tag on vehicles. Photo/video are often used for high volume highways. Labour requirements are more for tracing the ownership of vehicles and also may be less accurate but no disruption of traffic occurs.
c) Telephone survey
In this type of survey, appropriate vehicle owners are contacted on phone and are interviewed through a series of short questions. No disruption of traffic occurs but has high personnel requirements as compared to mail surveys. Some other advantages are low investments. This method has many disadvantages also like: appropriate sampling is difficult, low responses may create biased data, there is poor coverage of vehicles licensed in other states and areas.
d) Mail surveys
In this type of survey there is no disruption of traffic and also low investments are required. But obtaining trip details is difficult and also response rates are low which may create a biased data. Sampling is also difficult.
e) GPS Receiver
Cell phone tracking provides data on phone(owner’s) movements as cell phone transitions from one cell tower to another. But widespread utilization of GPS receivers for O-D data collection is currently cost prohibitive, especially for large rural and urban areas.Though there is no disruption of traffic, it requires very high equipment cost.This method is limited to samples only in the study area and also information regarding trip purpose is limited.
f) Online survey
Web-based surveys as compared to other surveys provide more valuable information less expensively. Response rate of these surveys can be very high if proper incentives are provided ,as the money saved for data input and validation can be used to boost up the response. Out of all Origin Destination survey methods these surveys provide ideal solution for information gathering because of their fast turnaround and can cover very large sample size. Sampling is difficult in this method though the response rate is very high and no disruption of traffic occurs.
