01559843

Component

https://doi.org/10.3141/2483-10

Motorists’ probabilistic yielding behavior is often observed at unsignalized crosswalks, but its impedance on traffic capacity has not been thoroughly examined. The uniqueness of this problem, which is also the challenge, is that neither pedestrians nor motorists hold absolute priority because of uncertainty in yielding behavior. Therefore, from the perspective of queuing theory, understanding the service mechanism is key to determining system performance. In this study, based on explicit analyses of complete yielding scenarios, the distribution of service time for queuing vehicles is derived. Traffic capacity is then determined on the basis of mean service time for queuers. In the special case of drivers fully respecting the priority of pedestrian flow, the capacity model reduces to the classic formula with absolute priority. The solutions from the proposed capacity model precisely match the results from stochastic simulations. To facilitate practical applications, an approximation is also developed that greatly simplifies the capacity formula but still gives very close estimations to the exact solutions. This simplified formula is recommended for practical applications. The proposed capacity formula, as well as the service time distribution, can also be applied to develop performance measures such as traffic delay and queue length through use of sophisticated queuing formulas.

01587923

15-3016

English

pp 80–90

2015

Transportation Research Record: Journal of the Transportation Research Board

9780309369268

Print

Figures (6) ; References (17) ; Tables (2)

Highway capacity; Queuing theory; Time; Traffic delays; Unsignalized intersections; Yielding

Unmarked crosswalks

Data and Information Technology; Highways; Operations and Traffic Management; Pedestrians and Bicyclists; Planning and Forecasting; I72: Traffic and Transport Planning; I73: Traffic Control

TRIS, TRB, ATRI

Dec 30 2014 1:01PM

• A German Approach to Freeway Facility Evaluation
• Average Delay at Unsignalized Intersections for Periods with Variable Traffic Demand
• Calibrating VISSIM for the German Highway Capacity Manual
• Effect of an Upstream Traffic Signal on the Capacity of a Downstream Two-Way Stop-Controlled Intersection
• Evaluation of Methodologies for Analyzing Freeway Ramp Weaving
• Field-Derived Freeway Passenger Car Equivalents for Congested Conditions
• Generalized Effects of On-Street Parking Maneuvers on the Performance of Nearby Signalized Intersections
• Generating Scenarios of Freeway Reliability Analysis: Hybrid Approach
• Generic Speed–Flow Models for Basic Freeway Segments on General-Purpose and Managed Lanes in Undersaturated Flow Conditions
• Methodology to Compute Travel Time of a Roundabout Corridor
• On the Treatment of Trucks for Analysis of Freeway Capacity
• On the Treatment of Trucks in Roundabout Analyses
• Planning-Level Methodology for Freeway Facilities
• Relationship of Lane Width to Capacity for Urban Expressways
• Risk-Taking Behavior of Left-Turners in Gap Acceptance and Its Effects on Capacity Estimation at Signalized Intersections
• Updated Commercial Truck Speed Versus Distance–Grade Curves for the Highway Capacity Manual