01049554

Component

https://doi.org/10.3141/2012-07

http://scholar.google.com...aiya&publication_year=2007

Freeway congestion monitoring can be based either on sampling-based methods, such as probe vehicle runs, or on continuous data from loop detector infrastructure. Sample size, in terms of the number of days sampled, affects the accuracy of sampling-based methods; detector spacing or detector density affects the accuracy of the detector-based method. This paper presents an empirical model of the effect of the two parameters—sample size and detector spacing—on the accuracy of both methods in estimating the annual average of three congestion parameters: total delay, average duration of congestion, and average spatial extent of congestion. The model is developed with data from four urban freeway corridors in California. Among other conclusions, the model predicts that to measure the congestion parameters with 10% error, 4 to 6 days’ worth of good probe vehicle data or loop detector data with half-mile spacing is needed. The proposed model facilitates comparison of the two alternatives in regard to the cost for achieving the same target accuracy. The result can also be used as a guide to determine the sample size or detector spacing in planning new congestion monitoring.

01084472

English

pp 57-63

2007

Transportation Research Record: Journal of the Transportation Research Board

9780309104388

Print

Figures (5) ; References (7) ; Tables (2)

Accuracy; Congestion management systems; Freeways; Highway corridors; Loop detectors; Mathematical models; Probe vehicles; Spacing; Traffic congestion; Traffic delays; Traffic surveillance

Sample size

California

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB, ATRI

Feb 8 2007 5:54PM

• Characteristics of Breakdown Phenomenon in Merging Sections of Urban Expressways in Japan
• Evaluating Benefits of A Systemwide Adaptive Ramp-Metering Strategy in Portland, Oregon
• Evaluation of Effects of Ramp Metering on Merging Operations
• Evaluation of Impacts of Open Road Tolling on Main-Line Toll Plaza
• Freeway Bottleneck Simulation, Implementation, and Evaluation
• High-Occupancy Vehicle Lanes and Hybrid Vehicles
• Improving Queue Size Estimation for Minnesota’s Stratified Zone Metering Strategy
• License Plate and Telephone Numbers in Changeable Message Sign Amber Alert Messages
• Methodology for Identifying Vulnerable Sections in a National Road Network
• Modeling Freeway Diverging Behavior on Deceleration Lanes
• Probabilistic Data-Driven Approach for Real-Time Screening of Freeway Traffic Data
• Safety Impacts of Freeway Managed-Lane Strategy: Inside Lane for High-Occupancy Vehicle Use and Right Shoulder Lane as Travel Lane During Peak Periods
• Simulation Analysis of Truck-Restricted and High-Occupancy Vehicle Lanes
• Traffic Diversion Effect of Ramp Metering at Individual and System Levels