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10 C H A P T E R 3 General Principles for Pedestrian Wayfinding and Crossing Tasks This chapter presents an overview of the design principles related to accessibility for pedestri- ans who are blind (subsequently referred to in this document as âblind pedestriansâ) that should be considered when designing a roundabout or CTL. The chapter is divided into a discussion of wayfinding tasks and an overview of the crossing tasks. In the following chapters, these principles are followed up with design principles specific to roundabouts and CTLs. 3.1 Wayfinding Tasks 3.1.1 Issues and Principles of Wayfinding at Intersections For pedestrians who are blind, crossing at roundabouts, CTLs, and other intersections consists of four task components, which are required for crossing any street (Guth, Rieser, and Ashmead, 2010): 1. Finding the crosswalk and determining the appropriate crossing location; 2. Aligning to cross and establishing the correct heading at the crosswalk; 3. Deciding when to initiate crossing (requiring the identification of appropriate gaps in traffic or crossing opportunities in front of yielding vehicles); and 4. Maintaining the correct heading while crossing and staying within the crosswalk. All but the third of these tasks are considered wayfinding tasks of crossing. Failure in any one of the three wayfinding tasks can result in actions such as crossing from a location where pedestrians are outside the crosswalk and thus unexpected by drivers, stepping into the roadway without realizing it, or crossing toward the center island of a roundabout. These tasks apply both to the initial approach to a crosswalk from the sidewalk as well as to wayfinding on roundabout splitter islands or CTL channelization islands. Failure in wayfinding tasks may lead to unsafe situations when negotiating splitter islands, potentially resulting in disorientation, walking into the street from the island, or aligning in ways that result in crossing into the intersection. Several examples of wayfinding errors are illustrated in Figures 3-1, 3-2, 3-3, and 3-4. Many strategies taught by certified orientation and mobility specialists to pedestrians who are blind or who have low vision were developed for typical intersection geometries and traffic flow patterns. Pedestrians who are blind may assume, even when crossing streets in unfamiliar areas, that the crossing will be at a corner and that vehicular traffic flow on the street beside them will be parallel to the direction of the crosswalk. They may also assume that the direction of traffic flow will be somewhat predictable due to signal phasing. These strategies and assumptions are
General Principles for Pedestrian Wayfinding and Crossing Tasks 11 Figure 3-1. Pedestrian initiating crossing outside the crosswalk and toward a roundabout circulatory roadway. Figure 3-1 shows a blind pedestrian lined up to cross toward the roundabout circulatory roadway during research trials. A cobblestone type of surface between the sidewalk and the roadway was not recognized as a non-walking surface by blind pedestrians. An orientation and mobility specialist is standing nearby. The crosswalk is visible approximately 20 ft to the left of the pedestrian. Figure 3-2 shows a pedestrian disoriented on a large paved CTL island, walking away from the crosswalk; an orien- tation and mobility specialist is following close by. Figure 3-2. Pedestrian disoriented on a large paved CTL island. not well-suited to the curvilinear traffic flow and large-radius corners that are characteristic of roundabouts and CTLs. Individuals who are blind usually do not receive ongoing training or orientation and mobil- ity assistance. They typically are provided with training and skills at the time they experience vision loss, or as a child and young adult (if blind since birth), and then use those skills in the future. It is assumed that they will take that training and apply the techniques taught to them
12 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities: A Guidebook Figure 3-3. Pedestrian walking on a splitter island rather than in a cut-through crosswalk. Figure 3-3 shows a blind pedestrian walking on the raised portion of the splitter island rather than in the cut- through crosswalk area, disoriented as she walks parallel to traffic. An orientation and mobility specialist is closely following her. Figure 3-4 shows a pedestrian using a long cane beginning to cross at a roundabout crossing. She is well-aligned with the detectable warning that denotes the street/sidewalk boundary and gutter but is aligned to the right of the crosswalk direction. Her heading will result in her contacting the raised island outside the crosswalk area and cut- through area. An orientation and mobility specialist is closely following her as she begins to cross. Figure 3-4. Pedestrian misaligned to cross at a roundabout. to plan routes and travel in unfamiliar areas independently, and they often do so. If they have a loss of vision or major change in their life circumstances, they may receive more training, but it is not routinely provided. People with more recent training may have had some experience and training on the layout of roundabouts and CTLs, but particularly for wayfinding, training cannot resolve the problem of a design that does not provide adequate cues and information to an individual who cannot see.
General Principles for Pedestrian Wayfinding and Crossing Tasks 13 3.1.2 Typical Wayfinding Techniques and Strategies 3.1.2.1 Determining the Appropriate Crossing Location In current practice, pedestrians who are blind and approaching an intersecting street with the intent to cross and continue in their current direction of travel, often assume there will be a crosswalk that is at least as wide as the width of the sidewalk on which they are approaching. They also assume that they are within the width of the crosswalk as they approach (Jacobson, 2013; LaGrow and Long, 2011), and that the crosswalk will continue across the street in the same direction that they have been traveling. They also may assume that vehicles idling on the street they want to cross are stopped at a stop line that is parallel to the direction of the crosswalk. The typical techniques used by a pedestrian intending to continue in their current direction of travel is to stop when they reach a curb or a location that seems to be a curb ramp, check features with their long cane and assess the traffic, and generally maintain their approach heading as their crossing heading. If they are planning to cross the street beside them (their parallel street), they usually continue as described above to the cross street, then turn around and walk back 6 ft to 10 ft and then turn toward the street beside them. This set of techniques is not effective at finding a crosswalk at a roundabout or CTL. If there is a landscape strip as a traveler approaches the intersection, a blind pedestrian may follow (i.e., trail) along the edge of that strip, looking for the intersecting sidewalk or curb ramp. If there is not a landscape strip, some individuals may follow the curb while using their long cane, looking for a sloped area that may be a curb ramp. This can be more difficult for individuals who are traveling with a dog guide, because dog guide users typically receive less tactile feedback about the walking surface in comparison to long cane users. There is no reason in general for pedestrians who are blind to use curb ramps, and many prefer to avoid them. Crossing within a crosswalk is important, however, and experienced travelers who are blind understand that curb ramps should be within the width of the crosswalks. Thus they may look for curb ramps with their long cane if they are uncertain about the location of a cross- walk (Barlow et al., 2010; LaGrow and Long, 2011). Figure 3-5 shows an example of a landscaping that is detectable by a blind pedestrian trying to locate a crosswalk at a roundabout. Figure 3-6 shows an example of gravel used to provide adequate separation at a CTL. Figure 3-7 shows an example that is not detectable under foot (for dog guide users) or by the use of a long cane. Fig ure 3-8 - shows an example of a detectable landscape separation that is not carried all the way to the crosswalk, and may thus pose wayfinding challenges. Detectable warning surfaces (also called truncated domes or truncated dome detectable warnings) are required at the base of curb ramps or where there is a level landing at the street level to provide information to pedestrians who are blind about the location of the edge of the street. They are intended to inform blind pedestrians about the end of the pedestrian way and the beginning of the vehicular way; they are not intended to provide directional information (Bentzen, Barlow, and Tabor, 2000; U.S. Department of Transportation, 2006; U.S. Access Board, 2011). The information intended to be provided by the detectable warning surface is that the next step will be into the street. Since curb ramps are required to be within the width of the cross- walk, some pedestrians who are blind look for the detectable warnings at curb ramps to confirm that they are within the crosswalk. If pedestrians who are blind use the strategy of crossing from where they first arrive at the curb at roundabouts without appropriate treatments, they are likely to cross into the circulatory roadway (see Figure 3-1). At CTLs, this strategy may result in crossing at a location that is not within the crosswalk, missing the island entirely, or encountering landscaping at the end of the crossing that makes it very difficult to get out of the lane.
14 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities: A Guidebook Figure 3-5. Detectable landscape separation at roundabout. Figure 3-5 shows a roundabout with adequate landscape separation between the sidewalk and the street. The separation is in the form of a 4 ft to 5 ft wide grass strip that follows the curvature of the road. Figure 3-6 shows a CTL with adequate landscape separation provided through a gravel surface. Figure 3-6. Detectable sidewalk separation at a CTL with gravel surface. 3.1.2.2 Aligning to Cross and Establishing the Correct Heading There are two primary strategies that are used by pedestrians who are blind to align to cross at a typical intersection. To establish a heading straight across the crosswalk to the desired location on the opposite side of the street, travelers often assume that they will be continuing to travel in the same direction as they were traveling as they approached the intersection. The first strategy is to use auditory and tactile cues to maintain that line of travel. The second strategy is to align with the sound of traffic proceeding straight ahead on the street beside them (Barlow et al., 2010;
General Principles for Pedestrian Wayfinding and Crossing Tasks 15 Figure 3-7. Sidewalk separation at a roundabout not detectable under foot or by the use of a long cane. Figure 3-7 shows a roundabout with separation between the sidewalk and the road provided through paving stones, which are not detectable under foot or by the use of a long cane. Figure 3-8 shows a CTL with gravel landscape separation between the sidewalk and the street that is not carried all the way to the crosswalk, and thus does not provide adequate wayfinding guidance. Figure 3-8. Sidewalk separation at a CTL not carried to the crosswalk. Guth, Rieser, and Ashmead, 2010; Stollof, 2005) and/or to square off (i.e., directly face the loudest point) of traffic moving perpendicular to their path. When traffic is flowing on the street beside them as they cross, it is assumed to be flowing in the same direction (i.e., parallel) as the crosswalk, helping with both initial alignment and maintaining alignment during crossing. This is a very effective strategy at intersections having typical geometry because the traffic is normally moving parallel to the crosswalk. However, at roundabouts and CTLs, the crosswalk is seldom straight ahead in line with the sidewalk as one
16 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities: A Guidebook approaches an intersection; instead, it is usually some distance around a large-radius corner and to oneâs side. At roundabouts, there typically is no traffic traveling parallel to the crosswalk. Traf- fic also may not be traveling perpendicular to the crosswalk, depending on the location of the crosswalk and the geometry of the roundabout or CTL. Some individuals may attempt to align with the traffic traveling across their path, which may work at some CTLs and roundabouts. The success of this strategy depends on the angle and location of the crosswalk in relation to the traf- fic movement and the curvature of the roundabout entry or exit or the CTL. Pedestrians who are blind may also cue on the street gutter and align themselves so that they are perpendicular to the gutter or the curb line on each side of the ramp. Curb ramps may or may not slope in line with the direction of crosswalks, and although slope may have some influence on alignment, it does not result in more accurate alignments (Scott et al., 2011a). In optimal design for wayfinding by pedestrians who are blind, curb ramps should slope in the direction of travel on the associated crosswalk. As noted earlier, detectable warning surfaces are not intended as an alignment cue and neither the pattern nor the edge of the detectable warning results in an accurate alignment for crossing (Scott et al., 2011b). Therefore, although they may affect alignment and crossing heading, neither the slope of the curb ramps nor the way in which the truncated dome detectable warnings are installed are usually considered to be reliable sources of information for aligning to cross. Despite that, many blind pedestrians attempt to use a combi- nation of the slope of the curb ramp, the gutter of the street, and the detectable warning surface as additional alignment information. While this is a strategy that does not work at all locations, it may be used by some blind pedestrians in the absence of other cues. Figure 3-9 is an example of a roundabout crosswalk aligned too far to the left of the crosswalk landing on the splitter island. Figure 3-10 is an example of a blind pedestrian aligning to cross at a CTL. Other cues for alignment include landmarks (objects or edges that are either parallel or per- pendicular to the crosswalk), although these usually require some familiarity with the specific intersection. More general alignment cues include other pedestrians, the direction of travel on the street to be crossed, and the location of idling cars. Physical cues such as grass lines and returned curbs (curbs along the edges of curb ramps) that are perpendicular to the street that is about to be crossed can be used if travelers are aware of their presence and know that they are aligned in the direction of the crosswalk (Hill and Ponder, 1976; Barlow et al., 2010). If such features are consistently available, pedestrians who are blind will begin to expect and use them. Some secondary cues for alignment may be useful at familiar roundabouts, but they are quite idiosyncratic and hard to anticipate and use in unfamiliar environments. 3.1.2.3 Maintaining the Correct Heading While Crossing and Staying Within the Crosswalk The primary strategy used by pedestrians who are blind to maintain their heading and travel straight across crosswalks at signalized and stop-controlled intersections is to travel parallel to the traffic moving straight ahead on the street beside them as they cross (Hill and Ponder, 1976; Jacobson, 2013). Straying from the crosswalk is a common problem for blind pedestrians and typically results from initial misalignment (Guth, Hill, and Rieser, 1989) or from veering from the initial alignment while crossing (Guth and LaDuke, 1994; Kallie, Schrater, and Legge, 2007; Rouse and Worchel, 1955). This is illustrated in Figure 3-11. The strategy of traveling parallel to traffic moving straight ahead on the street parallel to the direction of travel of the pedestrian is not useful at roundabouts because there is no traffic mov- ing straight ahead, parallel to the crosswalk. At a CTL, this strategy may work for the main part of the intersection, but again there is no parallel street for crossing the actual CTL.
General Principles for Pedestrian Wayfinding and Crossing Tasks 17 An accessible pedestrian signal or other treatment with audible message may serve as a far side audible beacon if present to help with maintaining heading. But for most crossings at CTLs and roundabouts, the accuracy of the initial alignment is likely to have a strong impact on the direction of travel, with limited audible or tactile cues available to correct initial alignment errors while crossing. As mentioned above, some individuals may attempt to align with traffic traveling across their path, or yielding to them near the crosswalk. The success of this strategy depends on the angle and location of the crosswalk in relation to the traffic lanes and the curvature of the roundabout entry or exit or the CTL. Figure 3-9. Roundabout crosswalk aligned too far to the left of the island landing. Figure 3-9 shows a roundabout with a crosswalk that is aligned too far to the left of the island for a wide three-lane crossing of a roundabout exit. Figure 3-10 shows a blind pedestrian aligning to cross at a CTL with detectable warning surfaces, ramp and gutter aligned with crossing, and the crosswalk perpendicular to the traffic flow. Figure 3-10. Blind pedestrian aligning to cross at a CTL.
18 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities: A Guidebook 3.2 Crossing Tasks 3.2.1 Issues and Principles for Determining When to Cross The task of determining the appropriate or safe time to cross the street is a key concern for the accessibility of roundabout and CTL crossings by individuals who are blind. The crossing task is a key focus, given that this task is likely to be the most risky of the four wayfinding and crossing tasks (i.e., determining crossing location, aligning to cross, determining when to cross, and maintaining the correct heading while crossing), because it directly exposes a pedestrian to the conflicting vehicle traffic stream. At unsignalized roundabout or CTL crossings, pedestrians who are blind have two types of crossing opportunities: (1) when there is a gap in traffic such that no approaching vehicle can reach the crosswalk before the crossing is completed or (2) when vehicles have yielded (Long et al., 2005). The yield crossing can be in the form of a voluntary yield maneuver by drivers or may involve crossing in front of vehicle(s) that have stopped or are stopping just upstream of the crosswalk for other reasons (e.g., roundabout entry queuing). For individuals who have total blindness, these decisions must be made using sound cues alone. Individuals with low vision may be able to visually observe vehicles stopping or visually detect a gap in traffic within certain distances or locations in relation to the crosswalk. 3.2.2 Typical Crossing Techniques and Strategies Strategies typically taught and used by pedestrians who are blind at both familiar and unfa- miliar street crossings may not be effective at roundabouts and CTLs. For example, crossing deci- sions at traditional intersections, such as stop-controlled or signalized intersections, are based on auditory cues from the somewhat predictable flow of traffic that aids blind travelers in selecting a relatively low risk time to begin crossing. At unfamiliar signalized intersections, pedestrians who are blind listen to determine the pattern of traffic movement, often for more than one signal cycle. They typically cross with the beginning of the movement of traffic in the near parallel lane Figure 3-11. Blind pedestrian maintaining crossing heading at signalized intersection. Figure 3-11 shows a blind pedestrian crossing a wide street in the crosswalk, with traffic moving on the street parallel to the crosswalk at a signalized intersection.
General Principles for Pedestrian Wayfinding and Crossing Tasks 19 of the street beside them, using that surge of traffic to indicate that the traffic parallel to their path has a green indication. They listen for traffic turning from the street beside them into the cross street across the crosswalk, since they know that many drivers do not yield to pedestrians, although pedestrians have the right-of-way. Accessible pedestrian signals further simplify the crossing decision by providing an audible indication of the onset of the walk interval. Learning the strategies for listening and making crossing decisions at signalized intersections is a common part of the orientation and mobility instruction for blind individuals. At unsignalized crosswalks, the typical technique taught to pedestrians who are blind or who have low vision is to cross when there is no traffic audible on the street they are crossing (Allen, 1997; Hill and Ponder, 1976; Jacobson, 2013). This applies to crossing the uncontrolled leg of a two-way stop-controlled intersection, crossing at a mid-block crosswalk, or crossing at a round- about or CTL. In other words, the recommended strategy is to wait for a long gap or an all- quiet period, which is a technique observed by several participants in roundabout studies as well (Schroeder et al., 2011). Of course, this strategy tends to become less effective as traffic volume increases and large gaps become rare (Figure 3-12). Individuals with visual impairments may have received instruction in timing strategies to determine that they can hear all vehicles far enough to be sure that a gap is adequate to cross the street (Barlow et al., 2010; Sauerburger, 2006). The timing strategy involves listening to or observing a number of vehicles and calculating the time that it takes for the vehicle to reach the crosswalk from the first moment that they hear each vehicle (Barlow et al., 2010). If it takes vehicles longer to reach the crosswalk following detection than the time it takes for pedestrians to cross the street, the assumption is that pedestrians will be able to cross using their hearing to determine a time to cross with minimal risk. To use this strategy safely, there must be gaps in traffic of adequate lengths of time as well as no other traffic that might mask the sound of a quieter, closer vehicle. At a very low volume roundabout or CTL, or at a low volume time of day, this may be an adequate strategy. Although some individuals will begin crossing an uncontrolled crosswalk when they perceive that a vehicle has yielded, others are reluctant to do so. Many certified orientation and mobility specialists instruct their clients not to cross in front of stopped vehicles. This is probably due to Figure 3-12 shows a single-lane roundabout in Charlotte, North Carolina, that typically has frequent all quiet periods that allow pedestrians to cross when there are long gaps in traffic. Figure 3-12. Single-lane roundabout with frequent all-quiet periods.
20 Crossing Solutions at Roundabouts and Channelized Turn Lanes for Pedestrians with Vision Disabilities: A Guidebook the inability of most clients to make eye contact with the driver, leading to difficulty in discern- ing the driverâs intentions and confirming that the driver is stopping for the pedestrian. It is not always clear whether the driver has indeed stopped to allow a pedestrian to cross or for some other reason, such as a stopped vehicle ahead. Some individuals who are blind or those who have low vision may elect to wait for a gap in traffic in the closest lane, then extend their long cane and begin crossing when they detect that a vehicle is yielding (slowing or stopped upstream) (Willoughby and Monthei, 1998). While more recent orientation and mobility textbooks mention crossing in front of vehicles that have yielded at single-lane locations, they caution against using that technique at multilane locations due to multiple threat concerns (LaGrow and Long, 2011). Travelers with visual impairments in these situations may use other strategies such as soliciting assistance or locating a nearby crossing that is signalized or stop-controlled.
