Pedestrian Crosswalk Signals at Roundabouts: TRB Roundabout Conference May 2005 Pedestrian Crosswalk Signals at Roundabouts: Where are they Applicable? Bill Baranowski, P.E. RoundaboutsUSA BACKGROUND The proposed American Disability Act (ADA) Guidelines have recommended that traffic signals be located at all roundabout crosswalks to improve pedestrian safety and to allow for the crossing of the visually impaired. There are many roundabout locations that may warrant a pedestrian signal and this paper shows some recent examples of successful installations and one roundabout location where the pedestrian signal was subsequently removed. Midblock crossing signal warrants are described in the USA and the UK. Many engineers and planners feel that the decision of whether to install pedestrian crosswalk signals at a roundabout should be based on engineering judgment and warrants and should not be mandated by a blanket policy. This paper includes: • Introduction to modern roundabouts; • US Access Board proposed guidelines at roundabouts; • Pedestrian signal thresholds/warrants in Great Britain and the USA; • Examples of roundabouts with pedestrian crosswalk signals; • Mid-block crossings at roundabouts; and • Insurance Institute for Highway Safety response to requiring crosswalk signals at roundabouts. MODERN ROUNDABOUTS There are an estimated 50,000 modern roundabouts worldwide, and more than 700 have been constructed in the United States since 1990. Many jurisdictions are now considering roundabouts to improve vehicle safety, increase roadway capacity and efficiency, reduce vehicular delay and emissions, and to identify community gateways. A typical modern roundabout (Figure below) is an unsignalized intersection with a circular central island and a circulatory roadway around the island. Vehicles entering the roundabout yield to vehicles already on the circulatory roadway. A dashed yield line for vehicles marks the outside edge of the circulating roadway at each entering street and defines the boundary of the circulatory roadway. Roundabouts have raised splitter islands at each approach that separate the entry and exit lanes of a street. These splitter islands are designed to deflect traffic and thus reduce vehicle speed. Splitter islands also provide a pedestrian refuge between the inbound and outbound traffic lanes. Engineers use a variety of design techniques, mostly geometric, to slow vehicles as they approach, circulate, and exit a roundabout. Design practices from Europe and in Australia continue to Page 1 of 15 Pedestrian Crosswalk Signals at Roundabouts: TRB Roundabout Conference May 2005 influence U.S. engineers as they refine design approaches for application in urban, suburban, and rural areas. Studies conducted in western Europe -- where roundabouts are common -- and in the U.S. have found that crashes at roundabouts are less severe than vehicular crashes at more traditional intersections. The reduction in serious vehicular crashes is the most compelling reason cited by transportation engineers for the installation of roundabouts. Roundabouts increase vehicular safety for two main reasons: 1) they reduce or eliminate the risk arising at signalized intersections when motorists misjudge gaps in oncoming traffic and turn across the path of an approaching vehicle; and 2) they eliminate the crashes that occur when vehicles are hit broadside by vehicles on the opposing street that have run a red light or stop/yield sign. The roundabout community anticipates that roundabouts will be built in the United States annually by the hundreds in the coming years and by the thousands annually, duplicating the trends first in Britain and Australia during the 1970s and 1980s and now being repeated throughout western Europe. For example, France went from 12,000 roundabouts in 1990 to over 23,000 roundabouts today. Most have been built since the mid-1970s. In 2001, there were 23,000 roundabouts in France resulting in 1,329 injury accidents, but only 86 involving pedestrians. US ACCESS BOARD The U.S. Access Board is a Federal agency that develops accessibility guidelines for buildings and facilities covered by the ADA and other laws. In 1999, the Board established a committee to make recommendations on accessibility guidelines for public rights-of-way. The members of the committee represented Federal agencies, traffic engineering organizations, State and local government transportation and public works agencies, traffic consultants, standard-setting organizations, and disability organizations. On January 10, 2001, the committee submitted its report to the Board recommending a new national set of guidelines for accessible sidewalks, street crossings, and related pedestrian facilities including access to roundabouts. http://www.access-board.gov/rowdraft.htm The report recommends: • pedestrian channelization by means of landscaping, railings, bollards with chains and similar devices where pedestrian crossings are prohibited; • cues (locator tones, detectable warnings, other) to identify crossing locations; • longer crossing times at signals (3.0 ft./sec walking speed); • pedestrian-activated signals at roundabout; and • Audible Pedestrian Signals (APS) at existing traffic signals. The Access Board is considering Committee recommendations as it adapts current ADA standards for more effective use in the public right-of-way. A draft guideline proposing pedestrian signals at all roundabout crossings was published in June 2002. Roundabouts seemed to be lumped together with free right-turns at all types of intersections. Many engineers and planners designing roundabouts feel that what the US Access Board is asking for in new roundabouts (the "guaranteed gap" for Page 2 of 15 Pedestrian Crosswalk Signals at Roundabouts: TRB Roundabout Conference May 2005 visually impaired pedestrians) is more stringent than what the visually impaired pedestrians are provided in typical signalized intersections, even in signalized intersections with audible signals. As long as there isn’t a protected pedestrian phase (which is the case for most intersections), pedestrians are in conflict with turning vehicles. Visually impaired pedestrians cannot detect turning vehicles at a signalized intersection. In fact it may be more difficult for a visually impaired person to detect a turning vehicle at a signalized intersection, than it is to detect an exiting vehicle at a roundabout. Many engineers ask why pedestrian signals are required for roundabout intersections when they are not required at all other intersections (All-way STOP, and uncontrolled intersections with marked crosswalks). There are many roundabout locations that may warrant a pedestrian signal and this paper shows some recent examples of successful installations and one roundabout location where the pedestrian signal was subsequently removed. Note that each of these locations met existing pedestrian crosswalk signal warrants established for signalized pedestrian signals in Australia and the USA. In the Clearwater Beach example, although a pedestrian signal was clearly warranted, it was later removed. It was found that this crosswalk was located far enough away from the circle to operate effectively without a pedestrian crosswalk signal. PEDESTRIAN CROSSWALKS AT ROUNDABOUTS Pedestrian crosswalks at roundabouts are provided to increase pedestrian safety and convenience without incurring excessive delays to traffic. These objectives will only be achieved if crosswalks are sited to attract the maximum number of pedestrians who would otherwise cross the street at random, and also to give drivers adequate opportunity to recognize them in time to stop safely. The common practice is to situate the crosswalk at least one car away from the roundabout entry line for single-lane roundabouts (25-ft.) and two or more car lengths away (45-50 ft.) from the entry line for dual-lane roundabouts. A refuge island with a minimum 10-ft. width is provided in the splitter island so that pedestrians are required to cross only one traffic stream at a time. PEDESTRIAN CROSSWALK SIGNAL WARRANTS IN THE USA The pedestrian signal warrants discussed here are for two types of pedestrian crosswalk signals: 1. Standard traffic signal with Green-Yellow-Red signals activated by a pedestrian pushbutton. 2. Flashing Yellow beacon or in-pavement flashers or a combination of the two activated by a pedestrian pushbutton. When the beacon is activated, vehicles must stop and let pedestrians cross the street. When the pedestrians have passed, the vehicles may proceed. The Manual on Uniform Traffic Control Devices (MUTCD) pedestrian crossing warrant criteria require fairly high pedestrian crossing volumes for extended periods of time. The MUTCD requires a minimum pedestrian volume of 100 or more pedestrians for four hours or 190 or more Page 3 of 15 Pedestrian Crosswalk Signals at Roundabouts: TRB Roundabout Conference May 2005 pedestrians for one hour. It is typically difficult to meet these warrant criteria. Other studies have recommended the following minimum pedestrian crossing volumes: The FHWA’s Pedestrian Signalization Alternatives Study recommended minimum pedestrian crossing volumes of 60 pedestrians per hour for four hours, 90 per hour for two hours, or 110 per hour for one hour. The volume requirement may be halved for elderly or handicapped pedestrians. The Ottowa-Carleton DOT pedestrian flashing crosswalk warrant criteria requires a minimum of 200 pedestrians crossing in an eight hour period, with a minimum range of 200 to 400 pedestrians