1. Roundabouts: How They Work for Pedestrians
Roundabouts can and do work for pedestrians, with few exceptions, most notably pedestrians who have vision impairments. Be ready for resistance from those who have a prejudice against roundabouts. Yet the safety record is well established: crashes are less than at conventional signalized or two way stop-controlled intersections. Safety is increased primarily because of several factors: reduced speeds, no left-turn conflicts, shorter crossing distances, and crossing only one direction of travel at a time.
Module 8
Golden CO

2. Roundabouts: Learning Objectives:
At the end of this module, you will be able to:
Explain why roundabouts reduce crashes
Describe the safety benefits for pedestrians and motor vehicles of roundabouts
Describe how roundabout safety depends on correct design
The first point is important: throughout the workshop we’ve been emphasizing the importance of slow speeds, reduced conflicts and eliminating left-turn conflicts. Roundabouts achieve these three goals, by design.
Designing for Pedestrian Safety – Roundabouts

3. Essential roundabout characteristics
Separated sidewalks direct peds to crosswalks
Bend OR
Slow speed exit
Splitter island
Truck apron
Animated. The red line indicates the path a vehicle travels through a roundabout. Start at the upper left and read items counterclockwise. Click to animate the red line just before you get to the “Slow speed entry” item.
Roundabouts are designed to have operating speeds between mph
Lots of deflection = slow speeds throughout
Crosswalk 1 car length back
Slow speed entry = yield

4. Roundabouts are a type (or subset) of circular intersections
All circular intersections
Others
Key Message: Not all circular intersections are roundabouts
Background:
The slide is intended to graphically convey this point that not all circular intersections are roundabouts. The modern roundabout is a type (or sub-set) of circular intersection within the universe of circular intersections in existence.
Additionally, roundabouts don’t always have to be round – they can be ellipses or ovals too!
Rotaries
Neighborhood traffic circles
Bottom Line: Not all circular intersections are roundabouts!!
Designing for Pedestrian Safety – Roundabouts

5. A roundabout is not: 1. A rotary, with large size & high speeds
The next few slides give examples of circular intersections that are not considered modern roundabouts. Many people confuse them with large rotaries, which can be intimidating to pedestrians because of their high speed.
It is important to go through these slides carefully, because much of the resistance comes from people’s experience with large rotaries in New England
Augusta ME
A roundabout is not: 1. A rotary, with large size & high speeds

6. Problems with Existing Rotary
Kingston NY
Large diameter (600 ft +)
No control of entry
High speed
Key Message: A major distinction between a traffic circle and a modern roundabout is their size.
Background:
Photo shows a prior traffic circle in Kingston, NY. The instructor should point out the large diameter (600 ft or more) of the circle allowed for higher speeds and even passing within the circulatory roadway. Note the design of the entry to the circle and how it allows a high speed entrance and also requires traffic to weave within the circulatory roadway. These features contribute to the poor performance of these older designs and to driver frustration using them.
Photo credit: NYSDOT
High speed weaving here

7. Rotary Reconstructed to Roundabout
Kingston NY
Smaller diameter
(Typically 120 – 250 feet)
Key Message: A modern roundabout is geometrically different from traffic circles
Background:
This is the same photo from the previous slide showing a modern roundabout being constructed within the center of the old traffic circle.
Although this example does not show pedestrian accommodations, it does show the contrast in size between the two.
Photo credit: NYSDOT

8. The circles in Washington DC, such as Dupont Circle, are nice urban spaces, but cannot be considered roundabouts. They are signalized and allow pedestrian access to the center circle.
Washington DC
A roundabout is not: 2. A Washington DC style circle, with traffic signal controls

9. A roundabout is not: 3. A traffic-calming mini circle
Mini-traffic circles lack many of the features of a roundabout, especially the splitter islands. They are appropriate on local streets.
Point out that there are NO splitter islands on the entries.
Also point out that this is NOT a mini roundabout. A mini roundabout has yield control on entry, a mountable center island and does include at least painted splitter islands.
A roundabout is not: 3. A traffic-calming mini circle

10. A roundabout is not: 4. Paris
Humor. This is the place de l’Etoile in Paris – at times of low traffic! It’s chaotic but it somehow works.
The person standing in the middle of the road is a police man who is helping direct traffic.
Paris FR
A roundabout is not: 4. Paris

11. Before and After Example
Asheville NC

12. Before and After Example
Asheville NC

13. Advantages for Pedestrians
Bird Rock, San Diego, CA
Reduced vehicle speeds
Reduced number of conflict points
Shorter crossing distances
Splitter island provides a refuge – ped crosses one direction of traffic at a time
Crosswalk is placed one car length back
Reduced vehicular speeds – typically 15 – 25 mph Have audience think back to the slide with the chances of surviving a crash at 20mph vs 40 mph
Reduced number of conflict points
Shorter crossing distances = reduced exposure time
Splitter island provides a refuge - Pedestrian crosses only one direction of traffic at a time
Cross walk is one car length behind yield line - this is an advantage because vehicles at a yield line are typically concentrating on accepting a gap to enter into the intersection and not on pedestrians wanting to cross the road
Photo Credit: Dan Burden

14. Vehicle-Pedestrian Conflict Points
Key Message: Pedestrian-vehicle conflicts are also reduced.
Background and Discussion: Pedestrians are generally safer at rdbts although a more active interaction may be necessary with the drivers similar to stop controlled intersections.
There are 32 vehicle-vehicle conflict points for the same scenario. Still only 8 v-v at a roundabout.
Conventional Intersection
16 Conflict Points
Roundabout
8 Conflict Points

15. Roundabout are Safer for All Users
Clearwater FL
Pedestrian crashes:
CMF = 0.73 (CRF = 27%)
All crashes:
Conversion from Two-way stop control:
All crashes: CMF = 0.56 (CRF = 44%)
Injury crashes: CMF = 0.18 (CRF = 82%)
Conversion from signal control:
All crashes: CMF = 0.52 (CRF = 48%)
Injury crashes: CMF = 0.22 (CRF = 78%)
27% reduction in ped crashes from Persaud, 2002
Other data based on NCHRP 672 (Roundabouts: An Informational Guide) and the CMF’s in the HSM; data from both documents come from NCHRP 572, Applying Roundabouts in the United States.
From NCHRP 572
This research did not find any substantial safety problems for non-motorists at roundabouts,
as indicated by few crashes being reported in detailed crash reports. In addition, no crashes
and a very small number of conflicts were observed from video recordings of interactions
between non-motorists and motorists. Because exposure data were not available from before
a roundabout was present, it is unknown whether pedestrians have altered their travel patterns
because of the presence of a roundabout.
• The ability of pedestrians and bicyclists to use the roundabout may be compromised if use of
the roundabout by all modes and their subsequent interactions are greater than studied herein
or if such interactions increase over time (i.e., as vehicle traffic and/or pedestrian traffic
increases).
• An emphasis needs to be placed on designing exit lanes to improve upon the behaviors of both
motorists and pedestrians.
• Multilane roundabouts may require additional measures to improve upon the behaviors of
motorists, pedestrians, and bicyclists.

16. Observational Pedestrian Safety Findings
Santa Barbara CA San Diego CA
Key Message: What might be more interesting the number of crashes is the behavior of both pedestrians and vehicles at cross walks. (Of course, the only fair way of considering this would be to compare a similar study at a TWSC and signal controlled intersection.)
Discussion: Review the data in the figures briefly. Refer participants to the report for more information.
This is from NCHRP There was very little pedestrian safety data available at roundabouts. However the pedestrian data did show more pedestrian crashes and multi-lane roundabouts than single lane roundabouts, which might be expected with Multiple Threat crashes.

17. Observational Pedestrian Safety Findings
Clearwater FL Bend OR
Key Message: What might be more interesting the number of crashes is the behavior of both pedestrians and vehicles at cross walks. (Of course, the only fair way of considering this would be to compare a similar study at a TWSC and signal controlled intersection.)
Discussion: Review the data in the figures briefly. Refer participants to the report for more information.
This is from NCHRP There was very little pedestrian safety data available at roundabouts. However the pedestrian data did show more pedestrian crashes and multi-lane roundabouts than single lane roundabouts, which might be expected with Multiple Threat crashes.

18. Pedestrian Movements at Roundabouts
This graphic is a close up showing how pedestrians cross. The most difficult crossing is not shown – from left to right across the exit lane. Most drivers do not signal a right turn, so the pedestrian cannot be sure whether an approaching vehicle is exiting or staying in the roundabout.
Pedestrians should not cross to the central island.
The graphic also illustrates how bicyclists are expected to use the roundabout, by taking the lane. Try to avoid belaboring bicyclists in roundabouts; in brief, the speeds are slow enough so they can confidently occupy the travel lane. The ramps are provided for those who choose to use the sidewalks and crosswalks.

19. Narrow entry slows drivers
Image: Dan Burden
Chico, CA
Narrow entry slows drivers

20. 1. At entry lane Well defined crossings & splitter islands
Yielding to pedestrians at entry lane is usually very high. Setting the crosswalk one car length back from the circulating roadway enables the driver to proceed forward and seek a gap in traffic after yielding to pedestrian, as that conflict is now behind him.
Bend OR
Well defined crossings & splitter islands

21. 2. At exit lane Well defined crossings & splitter islands
Yielding at the exit lane is less common, but with good design (slow speeds, clearly marked crosswalk) drivers will yield. Setting the crosswalk one car length back from the circulating roadway enables the driver to yield to pedestrians out of the circulating roadway.
2. At exit lane
Bend OR
Well defined crossings & splitter islands

22. Roundabout near Schools
There are well over 100 roundabout located next to schools in the United States.
Bend, OR developed a children’s activity book that is distributed to schools in Bend so students understand how roundabouts work and how they should cross roundabouts.
Photo Source: Ken Sides
Clearwater FL
Slow speeds improve safety at schools
There are 100-plus roundabouts at schools in the US

23. Lighting at Roundabouts
Center Mounted Lighting:
Peds visible only as silhouettes
Signs not visible
Key message: Example of lighting configuration and lighting level
Can you see the yield lines?
Layout is one location in central island
Overall the lighting is pretty good
Ped is visible in negative contrast but the signs are not
Needs approach lighting to be acceptable.
Study Source: Hasson and Lutkevich

24. Lighting at Roundabouts
Approach Mounted Lighting:
Peds illuminated
Signs illuminated
Key message: Example of lighting configuration and lighting level
This is good roundabout lighting using the peripheral lighting layout
Can see the signs approaching the roundabout
Can see the pedestrians in positive contrast
Study Source: Hasson and Lutkevich

25. Show why speeds can be faster in a multi lane roundabout and a multiple threat crash could occur.
It is generally better to use a single-lane roundabout instead of a multi-lane roundabout, even if future traffic volumes are anticipated to “require” a two-lane roundabout. Multi-lane roundabouts are much more complex for all users, and especially pedestrians. Some jurisdictions have designed a location for a two-lane roundabout, and only built a single-lane roundabout but constructed it so that it can easily be expanded, IF the predicted volumes occur at a later date.
Based on “Roundabouts: An Information Guide Second Edition” (NCHRP Report 672), the following volume thresholds can be used for planning level analysis of when a single-lane or two-lane roundabout will be sufficient – the lower volumes in each range are typical for high percentage of left turn movements.
Up to 17,000 vehicles per day: A single-lane roundabout is likely to operate acceptably;
Up to 26,000 vehicles per day: A single-lane roundabout may be sufficient but additional analysis is needed;
Up to 30,000 vehicles per day: A two-lane roundabout is likely to operate acceptably;
Up to 45,000 vehicles per day: A two-lane roundabout may be sufficient but additional analysis is needed.
These volume thresholds are based on fairly typical values for the ratio of peak hour to daily traffic, the directional distribution of traffic, the ratio of minor street traffic to total traffic, and the left turn percentage. Thresholds could be different at locations with unusual traffic volume characteristics.
Photo Credit: Mark Johnson
Monona WI
Multi-lane roundabouts have potential for “multiple threat” and higher speeds

26. Animated: Red line comes in automatically.
When traffic is light, a driver can easily proceed through multi-lane roundabouts at high speed by following a relatively tangential path, with little deflection.
Vail CO
Drivers may take a straighter, faster path on entry and exit, resulting in higher speeds – lane markings are recommended to minimize this

27. Roundabout concerns for peds with vision impairments:
This slide explains the problems reported by blind pedestrians, especially at multi-lane roundabouts.
Circulating traffic masks the sound cues used to identify gaps and masks the sound of yielding vehicles
Problems are much worse at multi-lane roundabouts
Golden CO

28. Possible Mitigation Measures for Blind Pedestrians at Multi-Lane Roundabouts
Public Right-of-Way Accessibility Guidelines (PROWAG, proposed rule July 26, 2011) require signals at multi-lane roundabout approaches:
Pedestrian Hybrid Beacon (HAWK)
Regular Red-Yellow-Green Signal
Research – other solutions may work:
Raised Crosswalk
Rectangular Rapid Flash Beacon
Ped signal may rest in dark (optional use by peds)
The PROWAG Notice of Proposed Rulemaking (NPRM) includes a similar requirement as the earlier PROWAG draft, requiring pedestrian signals at roundabout entrances or exits with more than one lane. This signal can be either a pedestrian hybrid beacon or a normal red yellow green signal.
If a pedestrian hybrid beacon is used at a roundabout, the pedestrian signal head is allowed to rest in dark, which means that it is optional for pedestrians to use it. Those who feel comfortable crossing without it don’t have to use it, those who feel they need it can press the button, and only then does the signal turn red for road users.
Recent research shows that other solutions may work. As shown in subsequent slides, research project NCHRP 674 found that raised crosswalks had similar success as pedestrian hybrid beacons at improving roundabouts for pedestrians with vision impairments. Other research is evaluating Rectangular Rapid Flash Beacons, to see what their effectiveness is.

29. Pedestrian Hybrid Beacon at Two-lane Roundabout
Golden CO
NCHRP 674 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities
Important to note that BOTH the hybrid beacon and the raised crosswalk showed promising results in terms of delay and risk.
Prior to treatment installation, the two-lane roundabout in this study showed average
O&M intervention rates on the order of 2.4% to 2.8% of crossings and average delays of
16 to 17 s to cross just one of the two legs (entry or exit) of the roundabout. While these
statistics shouldn’t be generalized across all two-lane roundabouts, the team believes that
the crossing performance could be even worse at higher-volume facilities and at roundabouts
with three-lane approaches, which should be the focus of future research.
Two treatments were tested at the two-lane roundabout location, both of which resulted
in notable improvements over the pretest condition. The tested treatments were a pedestrian
hybrid beacon (PHB, also known as a HAWK signal) and a raised crosswalk. Both resulted in
statistically significant decreases in pedestrian delay and crossing risk at the test locations.
The raised crosswalk treatment reduced average pedestrian delay from 17.0 s to 8.0 s. The
PHB reduced delay from 16.0 s to 5.8 s on average for crossing two lanes of traffic. The intervention
rates at the two studied crosswalks dropped from 2.8% of trials and 2.4% of trials
prior to installation to zero after installation of each of these treatments.

30. Raised Crosswalk at Two-lane Roundabout
Golden CO
NCHRP 674 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities
Important to note that BOTH the hybrid beacon and the raised crosswalk showed promising results in terms of delay and risk.
Prior to treatment installation, the two-lane roundabout in this study showed average
O&M intervention rates on the order of 2.4% to 2.8% of crossings and average delays of
16 to 17 s to cross just one of the two legs (entry or exit) of the roundabout. While these
statistics shouldn’t be generalized across all two-lane roundabouts, the team believes that
the crossing performance could be even worse at higher-volume facilities and at roundabouts
with three-lane approaches, which should be the focus of future research.
Two treatments were tested at the two-lane roundabout location, both of which resulted
in notable improvements over the pretest condition. The tested treatments were a pedestrian
hybrid beacon (PHB, also known as a HAWK signal) and a raised crosswalk. Both resulted in
statistically significant decreases in pedestrian delay and crossing risk at the test locations.
The raised crosswalk treatment reduced average pedestrian delay from 17.0 s to 8.0 s. The
PHB reduced delay from 16.0 s to 5.8 s on average for crossing two lanes of traffic. The intervention
rates at the two studied crosswalks dropped from 2.8% of trials and 2.4% of trials
prior to installation to zero after installation of each of these treatments.

31. Rectangular Rapid Flash Beacon at Multilane Roundabout
Olympia WA
FHWA study found some benefits to accessibility after RRFB installation at multilane roundabouts
Other impacts (volume, speeds, configuration) also impact yielding
Current research is being conducted on Rectangular Rapid Flash Beacons at multi-lane roundabouts. Full research results are not available yet (as of July 2011), but unofficially, researches have indicated positive results.
Photo credit: Brian Walsh, Washington State DOT.

32. Case Study: Great Neck Plaza, NY
Problem/Background
Small, dense, suburban community on Long Island
High pedestrian activity & older population
Busy central business district
High-use train station
Excessive vehicle speeds
Problem/Background: The Village of Great Neck Plaza is a small and densely populated suburban community, a third of a square mile in area, located in western Nassau County, New York. In addition to the bustling downtown central business district, the Great Neck train station of the Long Island Rail Road, as a key transportation hub for the entire Great Neck peninsula, generates considerable pedestrian and vehicle traffic as a key transportation hub for the entire Great Neck peninsula. Over 30 percent of the population in Great Neck Plaza is over 65 years of age. For many of these senior citizens, walking is their primary means of transportation. Yet the Village of Great Neck was faced with excessive vehicular speeds and lack of courteous driving. Given that older pedestrians often move and react more slowly than younger pedestrians, the Village felt it was necessary to take additional measures to create a safe pedestrian environment for all residents. Village officials wanted to increase the safety of local roadways and promote safer driving, walking and bicycling.

33. Case Study: Great Neck Plaza, NY
Solution
City received traffic calming grant from state DOT
Goal: calm traffic, enhance visibility of pedestrians, & improve crosswalk safety
4-way STOP replaced by roundabout
Contrasting pavement color, curb extensions, fencing, and islands used to direct traffic
Other locations: illuminated pedestrian crossings and speed awareness devices installed
Cost: $365,000 for the roundabout, $275,000 for the other improvements
Before
Solution: The Village awarded a grant through the "Local Safe Streets and Traffic Calming" (LSSTC) program offered by the New York State Department of Transportation. Several techniques were employed to accomplish the goals of calming traffic, enhancing the visibility of pedestrians, and improving crosswalk safety.
In , a four-way stop-controlled intersection adjacent to the Great Neck train station was replaced by the Barstow Road Roundabout. At this roundabout, contrasting pavement color was used to designate the crosswalk area, curb extensions shortened the crossing distance, decorative fencing directed pedestrians to the crossings, and splitter islands created medians on the approaches to the roundabout, allowing pedestrians to cross one direction of traffic at a time.
At other locations, the Village installed illuminated pedestrian crossings overhead to warn motorists of the presence of pedestrians entering or presence in the crosswalks. LED lights are activated by a pressure sensitive pad installed in the sidewalk handicap ramps. In addition, overhead speed awareness devices were installed on the four main roads leading to the central business district. The devices consist of a radar gun and digital readout of the actual speed of approaching vehicles.
The awarded grant provided 90 percent reimbursement through federal funds, with 10 percent provided by the Village of Great Neck Plaza for the local match. Total costs were $365,000 for the roundabout, and $275,000 for the overhead speed and motorist awareness signs.
After

34. Case Study: Great Neck Plaza, NY
Results
Pedestrian collisions reduced near the roundabout after installation
Users indicate a safer pedestrian environment
Vehicle flow improved
Effect of pedestrian crossing signs & speed warning devices not as good
Officials and residents consider project a success
Results: A review of collision data by the Village of Great Neck Plaza revealed a reduction in the number of pedestrian collisions in the vicinity of the Barstow Road Roundabout following its installation. Anecdotal data indicates that the roundabout has created a considerably safer pedestrian environment at the same time that it improved vehicle flow. The effect was not as great for the overhead pedestrian crossing signs and the speed warning devices, although they did have the effect of drawing attention to pedestrian presence on local roadways and creating a more welcoming environment for pedestrians. Village officials and residents consider the project a success.
Speed awareness device installed at same time as roundabout

35. Roundabout: Learning Outcomes
You should now be able to:
Explain why roundabouts reduce crashes
Describe the safety benefits for pedestrians and motor vehicles of roundabouts
Describe how roundabout safety depends on correct design
Recap of earlier learning outcomes.

36. Questions?