Variable speed limits (VSL) are dynamic traffic management systems designed to increase the efficiency and safety of highways. While the macroscopic performance of VSL systems is well explored in the existing literature, there is a need to further understand the microscopic behavior of vehicles driving in VSL zones. Specifically, driver compliance to advisory VSL systems is quantified based on a driving-simulation experiment and introduced into a broader microscopic behavior model. Statistical analysis indicates that VSL compliance can be predicted based upon several VSL design parameters. The developed two-state microscopic model is calibrated to driving-simulation trajectory data. A calibrated VSL microscopic model can be utilized for new VSL control and macroscopic performance studies, adding an increased dimension of realism to simulation work. As an example, the microscopic model is implemented within VISSIM (overriding the default car-following model) and utilized for a safety-mobility performance assessment of an incident-responsive VSL control algorithm implemented in a MATLAB COM interface. Examination of the multi-objective optimization frontier reveals an inverse relationship between safety and mobility under different control algorithm parameters. Engineers are thus faced with a decision between performing multi-objective optimization and selecting a dominant VSL control objective (e.g. maximizing safety versus mobility performance). / Master of Science / Variable speed limits (VSL) are dynamic traffic management systems designed to increase the efficiency and safety of highways. While the system performance of VSL systems is well explored in previous research, there is a need to further understand the individual behavior of vehicles driving under VSL control. Specifically, driver compliance to advisory VSL systems is modelled based on a driving-simulation experiment. Low compliance equates to poor VSL performance so it is important for engineers to have the ability to predict compliance based on VSL design conditions. The compliance model is introduced into a driver behavior model that quantifies and predicts the driver decision process on VSL controlled highways. The driver behavior model parameters are set using data obtained from the driving-simulation experiment. Utilization of the developed driver behavior model will increase the accuracy of future simulation work on VSL system performance. In this study, the model is implemented within a traffic simulation software to conduct an assessment of the trade-offs between safety and mobility VSL performance for different VSL control designs. An accident is modelled in the simulation software, and VSL is utilized to respond to and alleviate the incident. Simulation results indicate an inverse relationship between safety and mobility performance – indicating that engineers must select a primary objective when selecting VSL control design parameters.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/78234 |
| Date | 20 June 2017 |
| Creators | Conran, Charles Arthur |
| Contributors | Civil and Environmental Engineering, Abbas, Montasir M., Hotle, Susan, Rakha, Hesham A. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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