01099228

Component

https://doi.org/10.3141/2071-05

http://scholar.google.com...ehey&publication_year=2008

The "Highway Capacity Manual' (HCM) is the authoritative source providing state-of-the-art methodologies for evaluating highway, transit, bicycle, and pedestrian facilities. Default values are used to represent input parameters when the input parameters are difficult to measure or estimate. A default value is a representative value that may be appropriate for estimating an input parameter in the absence of local data. Before this study was done, no nationwide research effort had been conducted to assemble field measurements to determine whether the default values in the HCM represent typical field conditions. A sensitivity analysis was conducted for the input parameters in HCM 2000 that influence the service measures calculated in the HCM methodologies. Nineteen of these input parameters were determined to have a high degree of sensitivity in influencing the service measure results. These sensitive input parameters influence the service measures for the following HCM chapters: Urban Streets, Signalized Intersections, Pedestrians, Bicycle Paths, Multilane Highways, and Basic Freeway Segments. Based on the assembly of a nationwide database, specific default values were recommended for heavy vehicle percentages and peak-hour factors for uninterrupted flow facilities (freeways, multilane highways, and rural two-lane highways). It is recommended that default values for some input parameters continue to be developed based on existing HCM guidance. Other input parameters should be based on field measurements obtained from design plans. Additional guidance is provided to aid in the selection of default values based on the review of recent research documents.

01118256

English

pp 35-43

2008

Transportation Research Record: Journal of the Transportation Research Board

9780309113465

Print

Maps (1) ; References (13) ; Tables (2)

Bikeways; Freeways; Heavy vehicles; Highway capacity; Highway operations; Level of service; Multilane highways; Peak hour traffic; Pedestrians; Quality of service; Rural highways; Sensitivity analysis; Signalized intersections; Streets

Highway Capacity Manual

Default values

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB, ATRI

Jan 29 2008 3:18PM

• Analysis and Modeling of Automobile Users’ Perceptions of Quality of Service on Urban Streets
• Calibration Potential of Common Analytical and Microsimulation Roundabout Models: New England Case Study
• Capacity Reduction at Incidents: Empirical Data Collected from a Helicopter
• Control-Type Selection at Isolated Intersections Based on Control Delay Under Various Demand Levels
• Delay at Unsignalized Intersections
• Driver Behavior and Gap-Acceptance Characteristics at Roundabouts in California
• Estimating Capacity of U-Turns at Unsignalized Intersections: Conflicting Traffic Volume, Impedance Effects, and Left-Turn Lane Capacity
• Implementing Actuated Signal-Controlled Intersection Capacity Analysis with Pedestrians
• Inclement Weather Impacts on Freeway Traffic Stream Behavior
• Indicators of Performance on Two-Lane Rural Highways: Empirical Investigation
• Microscopic and Macroscopic Approaches to Delay Estimation with Oversaturated Conditions
• Modeling Left-Turn Blockage and Capacity at Signalized Intersection with Short Left-Turn Bay
• Multimodal Level of Service for Urban Streets
• Testing Incremental Queue Accumulation Method Using Lankershim Boulevard NGSIM Data Set: A Replacement for HCM Signalized Intersection Uniform Delay and Queue Method in Los Angeles, California