Compared to traditional methods of conducting Origin-Destination (O/D) surveys for analysing travel behaviour along major highway corridors, videotaping license plates in order to send out mail-back surveys to registered vehicle owners is generally superior for many reasons. Some of the more common problems run into, depending on the traditional type of survey method used, include interfering with traffic flow, aggravating motorists, creating possible safety risks to both the interviewers and motorists, collecting data from too small a sample, or collecting erroneous data. Even so, these traditional survey methods have tremendous staffing requirements. With the development of high-speed video photography, license plates can now be recorded on film and the vehicle owners sent mail-back surveys. Not only does the information obtained provide useful origin and destination information, but traffic counts can also be obtained at the same time with which the survey data can be compared for accuracy. Even though the response rate (typically 25% - 35%) is comparable to other mail-back surveys, the actual sample size is normally much greater and more representative of all the motorists using the corridor than by any other method. Also, fewer survey stations are required, eliminating costly staffing needs; there are no safety risks to motorists or surveyors; there is little to no chance of any double counting, and less chance of data biases due to the larger sample sizes and more accurate sampling (all lanes are sampled, not just selected on-ramps). This report will discuss the advantages and disadvantages of filming license plates as an Origin-Destination survey method compared to the more traditional methods. This report also discusses, as an example, th-D Survey conducted on t-SR-24 Interchange in Walnut Creek by the California State Department of Transportation.
Samenvatting