Overview
This case study is the fourth of five performed by the project team in order to validate the approaches to travel time reliability monitoring described in the Travel Time Reliability Monitoring Guidebook. The goal of each case study is to illustrate how agencies apply best practices for: monitoring system deployment; travel time reliability calculations; and agency use and analysis of the system. To accomplish this goal, the team is implementing prototype travel time reliability monitoring systems at each of the five sites. These systems take in sensor data from a variety of transportation networks, process this data inside a large data warehouse, and generate reports on travel time reliability for agencies to help them better operate and plan their transportation systems. This case study consists of the following sections:
- Monitoring System
- Methodological Advancement
- Use Case Analysis
- Lessons Learned
This monitoring system description section details the reasons for selecting the Atlanta region as a case study and provides an overview of the region. It briefly summarizes agency monitoring practices, discusses the existing sensor network, and describes the software system that the team used to analyze the use cases. Specifically, it describes the steps and tasks that the research team completed in order to transfer data from the data collection systems into a travel time reliability monitoring system.
The section on methodological advancement leverages methods developed in previous case studies to propose a framework for analyzing the impacts of non-recurrent congestion on a given facility’s operating travel time regimes.
Use cases are less theoretical, and more site specific. The first use case details the challenges of leveraging ATMS data to drive a travel time reliability monitoring system. The second use case compares the results of analyzing congestion with agency-owned infrastructure-based sensors and third-party provider speed and travel time data.
Lessons Learned summarizes the lessons learned during this case study, with regard to all aspects of travel time reliability monitoring: sensor systems, software systems, calculation methodology, and use. These lessons learned will be integrated into the final guidebook for practitioners.