The Perceptual requirements of these subtasks differ at roundabouts and traditional intersections.

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1 Slide 1 Human wayfinding and Intersection design Slide 2 Accessibility Slide 3 Accessibility involves assessing the traveller, assessing the environment, and then determining how the characteristics of both can best match Client: goals, physical limitations, perceptual limitations, orientation skills, mobility skills, use of tools and technology Environment: complexity, barriers to physical access, available information, risk level, ability to modify Everyday street crossing at intersection crosswalks: Locate the crosswalk Identify the crossing direction Determine when to begin crossing Stay within the crosswalk Monitor approaching vehicles as you cross and take evasive action if necessary The Perceptual requirements of these subtasks differ at roundabouts and traditional intersections. Slide 4 Facts about Roundabouts Prevalence: o US = 1 per 1,118 intersections o Germany = 1 per 313 intersections o Great Britain = 1 per 127 intersections o Spain = 1 per 96 intersections o Australia = 1 per 65 intersections o France = 1 per 45 intersections John Metcalfe, Citylab, 2016 US has 10,341 total (about 3,000 true roundabouts). Florida (1,283), California (683), Texas (487) are most prevalent Wide variations in design and vehicular capacity Evidence of increased safety

2 Slide 5 IMAGE: An overhead view of a roundabout. Entry and exit lanes and the splitter island on one leg are circled. Red lines indicate entry and exit lanes, vehicle stop lines, and the circulating lanes. Slide 6 IMAGE: A picture of a plus intersection Slide 7 IMAGE: A picture of the same plus intersection after being replaced with a roundabout. The same amount of land is used but the roads are paved with sidewalks and a round island is in the middle of the intersection. Slide 8 Finding the crossing place IMAGE: An overhead view of a roundabout in Nashville, Tennessee shows circulaitng lanes poorly demarcated and pedestrian walkways laid with confusing pavers. Slide 9 IMAGE: The sidewalk approach to a crossing of entry lanes at a roundabout. IMAGE: A sidewalk curving around where two streets come into a roundabout demonstrates how crossing places could be missed. Slide 10 Detectable warnings and tactual guidance surfaces IMAGE: A picture shows two people beginning to cross in a crosswalk. The pedetrians are stepping off a set of detectable warnings at the bottom of a wheelchair ramp. IMAGE: A diagram shows how tactual guidance surfaces could be used with detectable warnings to indicate where a crossing place exists. Slide 11 Identifying gaps

3 Slide 12 IMAGE: An aerial view of a large roundabout in Baltimore, Maryland Slide 13 IMAGE: Bar Graph. The graph shows the percentage of crossable gaps reported by pedestrians who are blind at several roundabouts. Slide 14 IMAGE: Bar Graph. The graph shows the latency for blind and sighted pedestrians in crossing in a crossable gap for entry and exit lanes at a roundabout. Slide 15 Small, single lane, residential-area roundabout in Tampa. Mid-day volume = 600 vehicles per hour Rush hour volume = 1300 vehicles per hour IMAGE: A picture shows a person with a dog guide waiting to cross at a roundabout. Slide 16 Traffic gap data IMAGE: traffic gap data.a graph shows the distribution of gap lengths at a roundabout at mid day. Slide 17 Traffic gap data IMAGE: traffic gap data. A graph shows the distribution of gap lengths at a roundabout at rush hour. Slide 18 Detecting gaps or creating gaps Can the pedestrian reliably detect gaps and yields? The multiple threat/multiple lane problem might be related to use of a strategy involving creating gaps by encouraging vehicles to yield.

4 What about pedestrians who cannot see or hear vehicles? Slide 19 Forcing driver yields IMAGE: yielding data. A bar graph shows the percentage of yields garnered by a arange of pedestrian behaviors. Slide 20 Examples of reversible step IMAGE: roundabout crossing. A video shows a pedestrian using the reversible step procedure to obtain a yield at the exit lane of a roundabout. Slide 21 IMAGE: intersection crossing. A video shows a pedestrian using the reversible step procedure to obtain a yield at a light controlled plus intersection. Slide 22 Further discussion Design changes to enhance access rumble strips signalization bollards tactile paving raised crosswalks Use of guide dogs intelligent disobedience multi-lane decision making decision/reaction time Slide 23 What are Alternative Intersections (AIS)? My definition

5 o An intersection treatment that provides improved traffic flow (especially for mainline traffic) by redirecting left and/or through movements. Similar problems to roundabouts Slide 24 Types of AIS Quadrant Roadway Median U-turn (MUT) o a.k.a. Michigan Left Superstreet o a.k.a. Restricted Crossing U-Turn (RCUT) Continuous Flow Intersection (CFI) o a.k.a. Displaced Left Turn (DLT) Diverging Diamond Interchange (DDI) o a.k.a. Double crossover diamond (DCD) Slide 25 Quadrant Roadway Left turns use an existing quadrant. Right turns get another option Pedestrians o Cross in same location at main intersection o Quadrant provides an additional crossing location IMAGE: Picture of a quadrant roadway intersection at a mall. A road going behind a mall is used to channel turning traffic away from the actual intersection. Slide 26 Median U-turn Eliminates protected left turns on all approaches IMAGE: East Beltline corridor in Grand Rapids, Michigan. An overhead shot of a series of median U turn intersections along a roadway. Slide 27 Restricted crossing U-turn (Superstreet) Eliminates protected left and through from side street

6 IMAGE: West Big Beaver Rd. and Lakeview Drive in Troy, Michigan. There is an overhead picture of a superstreet. Slide 28 Superstreet - Peds Side street same, may have channelized movement Mainline different, Z-crossing 2-stage crossings are safer for either mainline crossing Can cross at U-Turn also o If provided o Doesn t hurt vehicle progression o Ask for it! IMAGE: superstreet graphic. The graphic shows a generic plan for a superstreet intersection with indications of where pedestrians would cross. Slide 29 Continuous Flow Intersection (displaced left) Left turns crossover prior to main intersections Pedestrians..NOT GOOD sighted or impaired! IMAGE: There is an aerial view of a continuous flow intersection Slide 30 IMAGE: Diverging diamond interchange. Picture of a double diamond interchange. In this picture the shifting of lanes from right to left and back to right happens as the road goes over an interstate. Slide 31 IMAGE: Picture of double diamond interchange in Kansas. This overhead picture shows where pedestrians might walk at a double diamond interchange. To walk from one side of the interstate to the other, they must cross one channelized turn lane, navigate a large conccrete island, cross several lanes of traffic, naviagte a long concrete island with traffic on both sides that goes under the interstate, then cross several lanes of traffic, navigate another island, and cross another channelized turn lane. Slide 32 Engineering accessibility modifications

7 Slide 33 Shared streets Some shared streets examples IMAGE: Brighton, UK. Shared streets. There is a picture of a street where vehicles and pedestrians share the space. Slide 34 Smart environments Actuated intersections Traffic coordination Driverless vehicles Connected elements/smart cities Slide 35 Linking pedestrians to the environment Blind pedestrians have had to learn to interpret new intersections, traffic patterns, and features Rather than having all information gathering geared toward peds getting info, the environment needs to be an equal player Slide 36 Linking pedestrians to the environment Link blind peds to intermediaries for assistance (e.g., AIRA, Blindsquare, Look Around, imove, Seeing Assistant Move, Smart Ride) Standalone GPS systems (e.g., Trekker Breeze or Maestro, Kapten, Braillenote GPS) o Already being replaced by more integrated systems Truly integrated systems that combine two way information communication for ped navigation info and environment safety info (e.g., smartcities initiative, leveraging internet of things in Mobility-as-a-service Initiative)