Integrated Database and Analysis System for the Evaluation of Freeway Corridors for Potential Ramp Signaling
Ramp signaling is a traffic management strategy that aims to improve the flow of traffic by controlling the rate at which vehicles enter the freeway. While ramp signaling has been in use in the United States for more than half a century, the first such project in Florida did not go into operation until February 4, 2009, when ramp signals on the northbound section of I-95 in Miami-Dade County were first turned on for South Florida's traveling public. Before-and-after studies based on both travel time runs and detector data on the corridor have shown that the ramp signals significantly improved both the travel speeds and flow rates on the corridor. Building on this success, ramp signals have been scheduled to go into operation on April 14, 2010 for the southbound direction of the same corridor. In South Florida alone, District 4 is planning similar implementation on the I-95 section in Broward County and District 6 is considering the same for SR 826. In addition, the Miami Expressway Authority (MDX) is also likely to consider ramp signaling. Other districts, including 2, 5, 7, and the Turnpike, are expected to consider similar implementation as well.
Despite their newfound popularity in Florida, ramp signals may not be beneficial for all freeway corridors. For example, corridors that do not provide for traffic diversion via alternate routes may not be suitable for ramp signaling, nor will those that experience serious bottlenecks due to geometric constraints. Various guidelines exist to help transportation engineers and planners determine the suitability of specific corridors for ramp signaling. Proper evaluation of potential sites in accord with these guidelines requires the use of data currently maintained separately by various FDOT offices. This project will research and develop a system that will bring together several readily-available-but-scattered data sources for the purpose of analyzing corridor locations for the potential installation of ramp signals. These databases include:
- STEWARD (Statewide Transportation Engineering Warehouse for Achieved Regional Data) database, which will provide volume, speed, and occupancy data from detectors.
- Roadway Characteristics Inventory (RCI), which will provide mainly roadway geometric information, including number of mainline lanes, number of ramp lanes, lane width, acceleration lane length, ramp length, grades, existence of frontage roads, speed limits, etc.
- Florida Traffic Information (FTI), which will provide mainline and ramp volumes.
- Florida Traffic Safety Portal (FTSP), which will provide detailed, geocoded traffic crash records.
- "One-map" basemap, which will provide linear-referenced roadway segments for both the on- and off-system roads.
- SunGuide incident database, which will provide freeway incident data.
The integration of these databases will greatly assist in expediting what is often the most time-consuming part of a project. Once such a system is developed, it can also be used for other applications besides ramp signaling evaluation.
The goal of this project is to develop a web GIS system that integrates data from various databases that currently exist and operate independently. While the system will be designed for the purpose of ramp signaling evaluation, the integrated database to be developed will provide a database platform on which other applications can be built on. The specific objectives of this project include:
- Review and evaluate existing warranting criteria for ramp signaling.
- Develop a backend system to retrieve, process, and integrate data from various database sources.
- Develop an analysis system with the capability to analyze a corridor for its suitability for ramp signaling based on a set of pre-determined criteria.
- Develop a frontend system for easy user input and output visualization.