Breakdown probability model at freeway-ramp merges based on driver behavior

• Main Author: Kondyli, Alexandra
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2009
• Subjects: Behavioral psychology; Civil engineering
• ISBN: 1124294597; 9781124294599

A freeway-ramp merging model that considers vehicle interactions and their contribution to the beginning of congestion was presented. Focus group discussions were conducted to attain knowledge about drivers’ thinking process when merging. Three types of merging maneuvers were considered (free, cooperative, and forced), based on the degree of interaction between the freeway and the ramp merging vehicle. Field data collection was undertaken to quantify the effect of individual driver characteristics on their merging decisions and associate those with the breakdown occurrences at the freeway-ramp junctions. The data collection entails observations of participants driving an instrumented vehicle and simultaneous video observations of the freeway during these experiments. Behavioral characteristics of the participants were also evaluated. The collected data were used for calibrating driver behavior models that pertain to ramp vehicles’ gap acceptance decisions and freeway vehicles’ decisions to decelerate, change lanes or not interact subject to the ramp merging traffic, considering their behavioral attributes. A merging turbulence model was developed that captures the triggers for vehicle decelerations at the merging areas. The merging turbulence model due to vehicle interactions was evaluated through macroscopic observations at near-congested conditions. It was shown that the merging turbulence can be used as an indicator of the breakdown events.