01473534

Component

https://doi.org/10.3141/2389-02

http://scholar.google.com...eira&publication_year=2013

This paper reports on research that explored how multilane roundabouts located on urban corridors have affected traffic performance and pollutant emissions generated from vehicles. The research also compared the emissions of vehicles moving through the roundabouts as they used either the left or right entry lanes. The methodology can be generalized to measure the emissions of any multilane roundabout. The paper identified a representative speed profile for each speed trajectory type, no stop, one stop, and multiple stops, from field data collected at four multilane roundabouts in Aveiro, Portugal. The vehicle-specific power emissions methodology was employed to estimate the second-by-second emissions generated from a vehicle during different acceleration–deceleration cycles. Congestion-specific vehicle speed profiles for two-lane roundabout approaches were used to develop regression models to predict the percentage of vehicles that would experience different speed trajectory types in the roundabout. The analysis tested hypotheses about how differences in the following characteristics have affected the amount of emissions generated from vehicles in each lane: (a) the speed profiles in each lane (left versus right), (b) the conflicting flows for the left and right lanes, (c) the lane flow, and (d) the overall congestion levels. Under low congestion levels, vehicles in the right lane emitted more pollutant because they had on average higher speed and sharper acceleration and deceleration rates. For high congestion levels, given equal flow rates for the left and right lanes, vehicles in the left lane produced more emissions because vehicles in the left lane experienced longer stop-and-go cycles and had different speed profiles than did vehicles in the right lane.

01517322

13-0420

English

pp 12–21

2013

Transportation Research Record: Journal of the Transportation Research Board

9780309287142

Print

Figures (6) ; References (19) ; Tables (3)

Approach lanes; Exhaust gases; Methodology; Regression analysis; Roundabouts; Traffic congestion

Design; Environment; Highways; Operations and Traffic Management; I15: Environment; I73: Traffic Control

TRIS, TRB, ATRI

Feb 5 2013 12:13PM

• Event-Based Modeling of Driver Yielding Behavior to Pedestrians at Two-Lane Roundabout Approaches
• Influence of Sight Distance on Crash Rates and Operating Speeds at Low-Volume Single-Lane Roundabouts in the United States
• Prediction of Capacity for Roundabouts Based on Percentages of Trucks in Entry and Circulating Flows
• Roundabout Critical Headway Measurement Based on High-Resolution Event-Based Data from Wireless Magnetometers
• Safety Effects of Converting Intersections to Roundabouts
• Use of Computer Vision Data for Detailed Driver Behavior Analysis and Trajectory Interpretation at Roundabouts