This paper describes the methodology used, and results obtained, using GPS-derived continuous speed data and data from Bluetooth readers, to develop and calibrate a simple simulation model of a section of eastbound I-78 in New Jersey for the purpose of testing the potential effectiveness of various proposed ramp metering strategies.
In May, 2010, the New Jersey Department of Transportation retained AECOM and HNTB to perform a preliminary evaluation of ramp metering and associated technologies at four interchanges in the I-78 corridor between (but not including) US 22/NJ-31 and I-287 in Hunterdon and Somerset Counties.
To provide key inputs to this evaluation, AECOM developed a localized traffic micro-simulation model. This effort had three major components:
1. Collect new traffic volume and travel time data.
2. Develop the traffic simulation model and calibrate it to observed Spring, 2010 conditions.
3. Use the traffic simulation model to estimate the changes in operational conditions under each of the following conditions:
a. A “Future 2020 No Action” scenario.
b. A set of three 2010 “Build” scenarios incorporating alternative proposed ramp metering concepts.
c. A set of three “Future 2020 Build” scenarios combining the alternative proposed ramp metering concepts together with projected growth in traffic demand through 2020.
The data collection component made use of both emerging technologies (such as Bluetooth readers and INRIX continuous speed data) and conventional methods. The collection and use of the emerging technologies is the main focus of the paper although the conclusions on the potential benefits from the ramp metering scenarios will be shown.
The study concluded the following points:
• Both Bluetooth and INRIX provided high-quality data and showed a high degree of consistency with each other.
• The emerging technologies are in line with the data obtained using conventional data collection methods.
• The use of a sophisticated ramp metering system showed significant benefits as compared to no action or fixed-timed ramp metering .