01025677

Component

https://doi.org/10.3141/1965-01

http://scholar.google.com...anks&publication_year=2006

An alternative to the current approach to freeway bottleneck capacity analysis is outlined: average time gaps (average time separations between the rear of a vehicle and the front of one following it), average passage times (average times for vehicles to pass a point), and lane flow distributions serve as intervening variables to link geometric, vehicle population, and driver population characteristics to capacity flows. The first phase of research to evaluate this approach is described. The goal was to investigate interrelationships between the intervening variables and to relate them to average flow per lane under capacity conditions. Two types of “capacity condition”—pre-queue flow and queue discharge flow—were considered. Traffic data for 18 extended data collection periods at 15 bottlenecks in the Minneapolis–St. Paul, Minnesota; San Diego, California; and Seattle, Washington, areas were analyzed to calculate average values of critical lane time gaps (where the critical lane is that with the highest flow rate), critical lane passage times, and critical lane flow ratios (ratio of critical lane flow to flow per lane) and to relate them to average flows for periods of pre-queue and queue discharge flow. Critical lane average time gaps were not significantly correlated with critical lane flow ratios but were significantly correlated with average passage times and with flow per lane in both pre-queue and queue discharge flow; however, critical lane flow ratios were significantly correlated with flow per lane in queue discharge flow only. There is a strong, near-linear negative relationship between critical lane flows and critical lane average time gaps in both pre-queue and queue discharge flow.

01037212

English

pp 3-11

2006

Transportation Research Record: Journal of the Transportation Research Board

0309099749

Print

Figures (3) ; References (23) ; Tables (3)

Bottlenecks; Freeways; Highway capacity; Traffic flow rate; Traffic flow theory; Traffic models

Pre-queue flow; Queue discharge flows; Time gaps

Minneapolis (Minnesota); Saint Paul (Minnesota); San Diego (California); Seattle (Washington)

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB, ATRI

Mar 3 2006 10:37AM

• Continuum Traffic Model for Freeway with On-and Off-Ramp to Explain Different Traffic-Congested States
• Empirics of Multianticipative Car-Following Behavior
• Equilibrium of Lane Flow Distribution on Motorways
• Estimation of Driver Reaction Time from Car-Following Data: Application in Evaluation of General Motor–Type Model
• Estimation of Traffic Dynamics Models with Machine-Learning Methods
• Failure Detection and Diagnosis in Microsimulation Traffic Models
• Feedback Route Guidance Applied to a Large-Scale Express Ring Road
• Impact of Differences in Driver-Desired Speed on Steady-State Traffic Stream Behavior
• Impact of Lane-Change Maneuvers on Congested Freeway Segment Delays: Pilot Study
• Improvement and Evaluation of Cell-Transmission Model for Operational Analysis of Traffic Networks: Freeway Case Study
• Interdriver Differences in Car-Following: A Vehicle Trajectory–Based Study
• Modeling and Simulation of Unconventional Traffic Circles
• Piecewise-Linearized Cell Transmission Model and Parameter Calibration Methodology
• Point Constriction, Interface, and Boundary Conditions for Kinematic-Wave Model
• Preprocessing Volume Input Data for Improved Traffic Simulation
• Probabilistic Breakdown Phenomenon at On-Ramp Bottlenecks in Three-Phase Traffic Theory
• Reproducibility of Flow-Density Relations in Heavily Congested Flow Based on Individual Vehicle Data
• Short-Term Traffic Flow Prediction with Regime-Switching Models
• Simple Traffic Model for a Simple Problem: Sizing Travel Time Measurement Devices
• Time-Dependent Analysis of Density Fluctuations and Breakdown Thresholds on Congested Freeways
• Toward Demonstrating Predictability of Bottleneck Activation on German Autobahns