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Pages 161-173

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From page 161...
... HFG ROUNDABOUTS VERSION 2.1 30-1 C CHAPTER 30 ROUNDABOUTS Reducing Vehicle Speeds Approaching Roundabouts .............................................................. 30-2 Increasing Driver Yielding Rates for Pedestrians at Roundabouts ............................................
From page 162...
... HFG ROUNDABOUTS VERSION 2.1 30-2 REDUCING VEHICLE SPEEDS APPROACHING ROUNDABOUTS Introduction Reducing vehicle speeds approaching roundabouts provides more time for drivers to react to the presence of pedestrians and bicyclists crossing a roundabout approach or traveling through the roundabout. Research has shown that reducing vehicle speeds entering, traversing, and exiting roundabouts increases yielding rates to other vehicles, bicycles, and pedestrians.
From page 163...
... HFG ROUNDABOUTS VERSION 2.1 30-3 Discussion Pedestrian crossings at roundabouts can be more challenging than at traditional intersections for several reasons. If suitable gaps are available, drivers do not have to stop on the roundabout approach before merging into circulating traffic.
From page 164...
... HFG ROUNDABOUTS VERSION 2.1 30-4 INCREASING DRIVER YIELDING RATES FOR PEDESTRIANS AT ROUNDABOUTS Introduction Drivers generally do not stop when entering a roundabout if there is a sufficient gap in traffic circling within the roundabout. Drivers are often looking to their left, focused on evaluating gaps, as they approach a roundabout and are not always aware of pedestrians approaching a crossing from the right.
From page 165...
... HFG ROUNDABOUTS VERSION 2.1 30-5 Discussion Beacon Installation and Crosswalk Location: Several studies have found better driver yielding behavior at crosswalks at roundabout entries than at crosswalks at roundabouts exits (2, 5, 6)
From page 166...
... HFG ROUNDABOUTS VERSION 2.1 30-6 GUIDE SIGNING AT ROUNDABOUTS Introduction While the use of roundabouts has grown rapidly in the United States in recent years, they remain unfamiliar to many drivers. Drivers may exhibit less confidence when navigating a roundabout than they do at a traditional intersection.
From page 167...
... HFG ROUNDABOUTS VERSION 2.1 30-7 Discussion Although roundabouts have become more common in the United States, drivers are still relatively unsure about the proper way to navigate through a roundabout. This is largely because roundabouts involve high visual and perceptual demands due to the amount of information processing required (3)
From page 168...
... HFG ROUNDABOUTS VERSION 2.1 30-8 ACCOMMODATIONS FOR BICYCLISTS AT ROUNDABOUTS Introduction Intersections converted to roundabouts typically experience substantially fewer motor vehicle crashes; however, bicycle crashes can increase at roundabouts (1, 2)
From page 169...
... HFG ROUNDABOUTS VERSION 2.1 30-9 Discussion Jensen (1) found that bicycle crashes increased at intersections converted to roundabouts for almost all bicycle facility types.
From page 170...
... HFG ROUNDABOUTS VERSION 2.1 30-10 COUNTERMEASURES FOR IMPROVING ACCESSIBILITY FOR VISUALLY IMPAIRED PEDESTRIANS AT ROUNDABOUTS Introduction This guideline identifies countermeasures for improving accessibility for visually impaired pedestrians at roundabouts. Title II of the Americans with Disabilities Act (ADA)
From page 171...
... HFG ROUNDABOUTS VERSION 2.1 30-11 Discussion Landscaping: NCHRP Report 674 (2) and its related Guidebook in NCHRP Report 834 (4)
From page 172...
... HFG ROUNDABOUTS VERSION 2.1 30-12 ROUNDABOUT LIGHTING Introduction In order to safety navigate a roundabout, a driver must be able to clearly see the roundabout's layout and understand it's operations in sufficient time to make appropriate maneuvers, including yielding to pedestrians and accommodating cyclists. Lighting is used both to enhance the visibility of the roundabout from a distance and to improve the perception of the layout and visibility of other users for the driver during hours of low light and darkness.
From page 173...
... HFG ROUNDABOUTS VERSION 2.1 30-13 Discussion Lighting of roundabouts is important because headlights alone often cannot provide adequate illumination of the roundabout path due to the tight radius of the roundabout. When full lighting can be provided, the Illuminating Engineering Society's "Design Guide for Roundabout Lighting" (now part of "American National Standard Practice for Design and Maintenance of Roadways and Parking Facility Lighting")

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