01323679

Component

https://doi.org/10.3141/2173-05

http://scholar.google.com...stel&publication_year=2010

In the American as well as the German "Highway Capacity Manual," the quality of service that is determined by different measures of effectiveness can be described by six levels of service. While there are five levels (A to E) to distinguish undersaturated flow conditions, only one level of service (LOS) describes congestion. A differentiation of oversaturated traffic flow conditions (LOS F) is not possible so far. As traffic networks have become more and more congested this is insufficient, and instruments are needed to identify the worst bottlenecks. The paper presents approaches for a division of LOS F into differentiated sublevels of saturated flow (F1 to F4) and proposes corresponding calculation methods. Different traffic flow models and queuing equations are considered for the estimation of travel times as a function of traffic demand. Four potential methods for standardization are discussed that differ in the performance measures used. They are described by using freeway sections as an example, but they can be applied for all types of road facilities. The methods are analyzed and compared in terms of their significance, their sensitivity, and the availability of input data. On that basis, a 24-h analysis of traffic performance is recommended for implementation within the guidelines because it is able to evaluate congestion in a multidimensional way. The evaluation methods developed within this research can be used to assess the quality of service on existing congested facilities depending on traffic demand. They can help decision making and ensure that funds are spent efficiently.

01323680

10-2208

English

pp 36-44

2010

Transportation Research Record: Journal of the Transportation Research Board

9780309160438

Print

Figures (3) ; References (33)

Bottlenecks; Highway capacity; Level of service; Quality of service; Traffic congestion; Traffic flow; Traffic queuing; Travel time

German Highway Capacity Manual; Highway Capacity Manual

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB, ATRI

Dec 21 2010 2:33PM

• Analysis of Left-Turn Saturation Flow Rates and Capacity at Signalized Intersections
• Assessing the Benefits of Incident Management Systems: Combining Freeway Facility Procedures from the "Highway Capacity Manual" and Data Archives of Intelligent Transportation Systems
• Categorizing Freeway Flow Conditions by Using Clustering Methods
• Consistency of Stochastic Capacity Estimations
• Control Delay at Signalized Diamond Interchanges Considering Internal Queue Spillback
• Empirical Analysis of Effects of Wait Time and Rain Intensity on Driver Left-Turn Gap Acceptance Behavior
• Estimating Performance on Two-Lane Highways: Case Study Validation of a New Methodology
• Estimating Sustained Service Rates at Signalized Intersections with Short Left-Turn Pockets: Mesoscopic Approach
• Impact of Left-Turn Spillover on Through Movement Discharge at Signalized Intersections
• Level of Service: 2010 and Beyond
• Modeling Impedance Effects of Left Turners from Major Streets with Shared Short Lanes at Two-Way Stop-Controlled Intersections
• Modified Critical Movement Analysis Approach for Signalized Intersections
• Pedestrian Delay at Signalized Intersections with a Two-Stage Crossing Design
• Predicting Arrival Flow Profiles and Platoon Dispersion for Urban Street Segments
• Urban Street Performance: Level of Service and Quality of Progression Analysis