01091667

Component

Lots of urban intersections are characterized by geometric and functional features such as to disprove their operational analysis through usual models based on gap-acceptance theory. This can be observed both for unsignalized intersections where the priority rule is given to cars coming from the right and for roundabouts where the priority rule is assigned to the circulating vehicles. The operational conditions in the urban context furthermore are affected by a strongly random component due to unconventional users behaviours, i.e. users giving their priority, or users entering into the intersection and ignoring the give-way sign. Based on these considerations the authors deem that performances of urban atypical intersections can be established only through a theoretical-empirical approach that puts in a fair equilibrium the need both to match field observations and to have a general criterion of performance analysis. In this paper an example of such an approach is shown for multilane-large diameter not-conventional roundabouts (MLLD roundabouts) for which a pattern of a consensus of right-of way – similar to all-way-stop-controlled intersections (AWSC intersections) – was observed. The complexity of the approach for these intersections is evident when one also considers that behavioral parameters necessary to develop the model are difficult to be observed. For this purpose, macroscopic observations of operational conditions are used in a regression model in order to provide the unknown behavioral parameters; the presence of response correlation within a cluster of observations has required the development of a marginal model, i.e. to estimate the unknown parameters through Generalized Estimating Equations (GEEs).

01091711

English

14p

2007

3rd Urban Street Symposium: Uptown, Downtown, or Small Town: Designing Urban Streets That Work

CD-ROM

Figures (3) ; References (17) ; Tables (7)

Behavior; Drivers; Highway operations; Highway traffic control; Intersections; Macroscopic traffic flow; Multilane highways; Right of way (Traffic); Roundabouts; Urban areas

Multilane roundabouts

Design; Highways; Operations and Traffic Management; Planning and Forecasting; I21: Planning of Transport Infrastructure; I73: Traffic Control

TRIS, TRB

Mar 28 2008 10:37AM

• A History of Pedestrian Signal Walking Speed Assumptions
• A Model of Potential Capacity of Right Turn Movement at Signalized Intersections Under Mixed Traffic Conditions
• Analysis of Multifunctional Traffic Environments
• Analyzing Raised Crosswalks Dimensions Influence on Speed Reduction in Urban Streets
• Applying Context Sensitive Techniques to Improve Design and Gain Stakeholder Support
• Benefits and Risks of Urban Roadside Landscape: Finding a Livable, Balanced Response
• Cross Section Width for Parallel Parking
• Design and Traffic Organization for Ultra-Wide Urban Street in China
• Designing Inside the Box - Strategies to Successfully Marry Smart Growth and Context-Sensitive Transportation Initiatives
• Designing Streets for Enhanced Transit Service: The Jerusalem Experience
• Driveway Design Practices, Issues, and Needs
• Estimating Running Time on Urban Street Segments
• Four-Lane to Three-Lane Conversions: An Update and a Case Study
• Geometric Design of Interchange in Urban City
• Improving Pedestrian Safety at Unsignalized Intersections
• Integrating Context Sensitive Solutions into University Transportation Education
• Involving the Public in Redesigning Urban Street Layouts in the UK
• Iowa's Experience with 2-Lane to 3-Lane Conversions
• Iowa's Experience with 4-Lane to 3-Lane Conversions
• Minnesota CSAH 42: A Case Study Illustrating Traffic Signal Removal as an Access Management Strategy
• Pedestrian Crossings Priority for Pedestrian Safety
• Recent Superstreet Implementation and Research
• Responding to the Challenges of Bicycle Crossings at Offset Intersections
• Retrofitting Urban Arterials into Complete Streets
• Review of Guidelines for Establishing School Speed Zones
• Safety Effect of the Skew Angle in Right Turn Maneuvers
• Separation Between Pedestrians and Bicyclists
• Shared-Use Streets – An Application of “Shared Space” to an American Small Town
• Should Direct Left-turns from Driveways be Replaced by Right-turns Followed by U-turns? The Safety and Operational Comparison in Florida
• Speed: How Can We Get What We Want?
• St. Louis Great Streets Initiative
• Study on the Relationship of Intersection Design and Safety of Urban Unsignalized Intersection in China
• Study on the Safety Relationship between Left-turn Gap Acceptance and Waiting Time
• Sustainable Urban Street Design and Assessment
• Synthesis of the Median U-Turn Intersection Treatment, Safety, and Operational Benefits
• Traffic Calming in Slovenia
• Urban Street Reconstruction with Cultural Consideration-Research and Case Studies
• Yielding Behaviour and Interaction at Bicycle Crossings