On-Road Evaluation of Emission Impacts of Roundabouts

Reduced emissions and improved air quality are typically attributed to the use of roundabouts rather than traditional stop or signal control. Roundabouts are expected to reduce emissions as a result of reduced delays and stops. However, roundabouts slow all vehicles to speeds at which emissions may be higher, while signals stop and delay only a portion of vehicles. Roundabouts may also increase the amount of acceleration and deceleration for all vehicles. Because emissions are correlated to these modal events, their impacts should be considered in the evaluation of roundabouts. An on-road assessment of the emission impacts of two roundabouts compared with other types of traffic control was conducted with a vehicle instrumented with a portable emissions monitor. Emissions were measured along two corridors in Woodbury, Minnesota, with two drivers. The corridor at Bailey Road had two four-way stop-controlled intersections, one roundabout, and one signal. The corridor at Lake Road had one four-way stop, one roundabout, and one signal. Intersection spacing and traffic parameters were similar along each corridor. Emissions were compared for sections 750 ft upstream and 750 ft downstream of each intersection. Traffic conditions during data collection along both corridors were uncongested. Average emission rate by driver was compared for the three types of traffic control. Results suggested that emissions were highly dependent on driver behavior. The roundabouts did not necessarily have lower emissions than traditional stop or signal control.

• Record URL:
  https://doi.org/10.3141/2265-25
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=On-Road+Evaluation+of+Emission+Impacts+of+Roundabouts&author=S.+Hallmark&author=B.+Wang&author=A.+Mudgal&author=H.+Isebrands&publication_year=2011
• Availability:
  • Find a library where document is available. Order URL: http://www.trb.org/Main/Blurbs/166819.aspx
• Authors:
  • Hallmark, Shauna L
  • 0000-0001-5187-8022
  • Wang, Bo
  • Mudgal, Abhisek
  • Isebrands, Hillary
• Publication Date: 2011

Language

• English

Media Info

• Media Type: Print
• Features: Figures; Maps; Photos; References;
• Pagination: pp 226-233
• Monograph Title: Highway and Traffic Safety: Vehicles, Behavior, and Roundabouts
• Serial:
  • Transportation Research Record: Journal of the Transportation Research Board
  • Issue Number: 2265
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Air quality; Behavior; Drivers; Environmental impacts; Exhaust gases; Multiway stop signs; Roundabouts; Signalized intersections
• Geographic Terms: Woodbury (Minnesota)
• Subject Areas: Environment; Highways; Operations and Traffic Management; I15: Environment; I73: Traffic Control;

Filing Info

• Accession Number: 01337911
• Record Type: Publication
• ISBN: 9780309223027
• Report/Paper Numbers: 11-0698
• Files: TRIS, TRB
• Created Date: Apr 27 2011 7:20AM