Vehicle Occupancy Data Collection Methods, Phase II
As congestion management strategies begin to put more emphasis on person capacity than vehicle capacity, the need for vehicle occupancy data has never been greater. Unlike counting vehicles, which can be done with machine counters, counting the number of persons in a vehicle remains the task of human observers. As such, collecting vehicle occupancy data is a relatively costly task that requires careful planning and considerations. In the face of budget constraints, agencies must apply collection methods that strike a good balance between data accuracy and data acquisition cost.
Recognizing the increasing need for vehicle occupancy data, the Florida Department of Transportation (FDOT) undertook a study in 1996 and 1997 to collect over 2,000 hours of vehicle occupancy data from 21 sites around the state. The data were used to analyze variations across different locations, lanes, directions, times of day, days of week, months of year, and seasons of year. Following this data collection and analysis effort, FDOT conducted a second study last year to examine the different methods available to estimate vehicle occupancy. The project reviewed both existing and potential methods of occupancy data collection, examined issues related to geographic, temporal, and vehicle coverage design of occupancy data, and developed guidelines for performing data collection. Sampling plans for corridor and regional studies using different methods were presented. A user-friendly software system that can calculate occupancy rates from crash records was developed. Also developed was a Pocket PC application designed to collect occupancy data in the field to avoid manual data entry.
Building on the foundation of the previous studies, this study aims to achieve the following objectives:
- To collect field data to evaluate existing methods of vehicle occupancy data collection with respect to their accuracy, cost-effectiveness, and practicality.
- To present detailed deployment guidelines for the collection of vehicle occupancy data.
- To develop vehicle occupancy prediction model as a function of local socio-economic data.
- To evaluate and refine the field data collection tool developed in the first phase of this project.
- To evaluate and refine the FAVORITE (Florida Accident Vehicle Occupancy Rate InformaTion Estimator) system.
The goal of these objectives is to help agencies to identify methods that can meet the need for data accuracy in the most cost-effective manner.