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Improving Pedestrian Safety at Unsignalized Crossings (2006)

Chapter: Chapter 2 - Pedestrian Characteristics

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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
×
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
×
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
×
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
×
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
×
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Suggested Citation:"Chapter 2 - Pedestrian Characteristics." National Academies of Sciences, Engineering, and Medicine. 2006. Improving Pedestrian Safety at Unsignalized Crossings. Washington, DC: The National Academies Press. doi: 10.17226/13962.
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6Why People Walk The decision to walk usually takes into account the distance of the trip, the perceived safety of the route,and the comfort and convenience of walking versus an alternative mode (2).Distance is the primary factor in the initial decision to walk. Most pedes- trian trips (73 percent) are 0.5 mile (0.8 km) or less (3, 4) in length, with 1 mile (1.6 km) generally being the limit that most people are willing to travel on foot. Effects on the perceived and actual safety of pedestrians include sidewalks that are too nar- row or adjacent to moving lanes of traffic along with pedestrian crossings that are intimidating because of confusing signal indi- cations,excessive crossing distances,or fast-turning vehicles.The immediate physical environment also affects the comfort and convenience of walking. For example, shade trees or places to sit and rest may encourage pedestrian activity. The appearance of buildings, landscaping, and the street itself can contribute to a pleasant visual environment. A 1990 Harris Poll found that 59 percent of all respondents would be willing to walk more often if there were safe, designated paths or walkways (5). The 1995 Nationwide Personal Transportation Survey found person-trips to be distributed as follows: 5.4 percent walking, 86 percent private vehicles, 1.8 percent transit, 1.7 percent school bus, and 4.9 percent other (3). The 1995 survey also determined trips by trip purposes (see Table 2). The Washington State DOT’s Pedestrian Facilities Guide- book (4) determined similar purposes for pedestrian trips: • To and from work and school, • Social visits and events, • Appointments, • Health and exercise, • Errands and deliveries, • Recreation, • Extracurricular activities, • Combined (recreational walking while shopping), and • Multimodal trips (walking to a bus stop). Psychology of Space To attract pedestrians to a place, these key psychological principles should be considered (6): • Security. Streets with cars moving too fast or making too much noise or streets with too many hidden pockets, too little activity, places that are dark, isolated, or broken up by “dead” corners, open parking lots, blank walls, or block- long voids tend to dissuade people from walking there. • Comfort. Streets should have basic amenities such as enough sidewalk space, separation from the street, an edge or transition between uses of space, shade, and rich visual scenery to attract the pedestrian. • Convenience. Streets must provide a blend of services and economic life for the pedestrian. • Efficiency and Affordability. Streets that are overly expen- sive for the volume and categories of people that will use them cannot pay their way, but the quality of a street should not be compromised. • Welcoming Feeling. People must feel welcomed by the place and inspired to return, a feeling imparted by the employees of an establishment, by the people that share that street, and by the physical presence of the street itself. Why People Do Not Walk According to Washington State’s Pedestrian Facilities Guide- book (4), pedestrian trips account for 39 percent of all trips less than 1 mile, ranking second only to private motor vehicle trips. Despite this percentage, walking typically composes only 1 to 4 percent of all commuter trips in the United States over- all (4). Common reasons for low levels of pedestrian travel include • Poor facilities or lack of sidewalks or walkways, • Failure to provide a contiguous system of pedestrian facilities, C H A P T E R 2 Pedestrian Characteristics

• Concerns for personal safety, • Failure to provide facilities to and from popular origins and destinations, • Inclement weather, • Poor lighting, and • Lack of facilities separated from the roadway. Pedestrian Settings Urban Areas Americans tend to walk more in urban cities with large pop- ulations occupying a small area, such as New York City, a city in which 70 percent of the population does not even own a car. Heavy traffic flow on roadways and limited or expensive park- ing facilities in these towns make walking seem the easier, faster, and cheaper choice. In addition, many large cities with higher pedestrian populations (such as Boston; Washington, D.C.; Chicago; and San Francisco) also offer access to efficient public transportation systems such as subways that attract pedestrian users. Other cities (such as Portland, Oregon; Seattle, Washing- ton; and Boulder, Colorado) have increased pedestrian popula- tions because of rigorous efforts by lawmakers and police officials to make and enforce laws to encourage and protect pedestrian activity. Following are further explanations for why urban areas have high pedestrian use (4): • Traffic congestion is high. • Origin and destination points are more numerous and denser in concentration. • Shopping and services are more accessible to pedestrians. • Average trip distances are shorter. • Parking is too costly or unavailable. • Transit service is more readily available. • More pedestrian facilities are available. Suburban and Rural Areas Pedestrian travel is higher in urban areas, but pedestrians can also be found in suburban and rural areas. Suburban and rural pedestrian trips are often associated with walking to schools, school bus stops, or transit bus stops or for recre- ational and leisure purposes. Fewer people walk to run errands and shop or to reach community services (4). Walking Speed Pedestrians have a wide range of needs and abilities. The MUTCD (1) includes a speed of 4.0 ft/s (1.2 m/s) for calcu- lating pedestrian clearance intervals for traffic signals. The MUTCD also includes a comment that, where pedestrians routinely walk more slowly than normal or use wheelchairs in the crosswalk, a walking speed of less than 4.0 ft/s (1.2 m/s) should be considered in determining the pedestrian clearance times. Other research studies have identified pedestrian walking speeds ranging from 2.0 to 4.3 ft/s (0.6 to 1.3 m/s) as discussed in the following sections. The Institute of Trans- portation Engineers (ITE) Design and Safety of Pedestrian Facilities cited walking speeds up to 8 ft/s (2.4 m/s) (7). Pedestrians with Walking Difficulty A significant proportion (as much as 35 percent) of pedestrians—children, older pedestrians, and persons with disabilities—travels at a slower pace (8). Therefore, the slower walking speeds of these groups could be considered when determining pedestrian clearance intervals for traffic signals in locations with a high percentage of pedestrians with walking difficulties. An Australian Institute of Trans- portation (9) study of intersection signalized crossing sites identified the walking speeds of “pedestrians with walking difficulty” (irrespective of age) including older persons, people with disabilities, and parents pushing a baby stroller and/or paying attention to a young child walking alongside, a group which constituted 6 percent of the total sample size. The summary of results is reproduced in Table 3. Older Pedestrians In the Guidelines and Recommendations to Accommodate Older Drivers and Pedestrians report (10), an assumed walking speed of 2.8 ft/s (0.9 m/s) is recommended for less capable (15th percentile) older pedestrians with shorter strides, slower gaits, and exaggerated “start-up”times before leaving the curb. Mean start-up time (from the start of the Walk signal to the moment the pedestrian steps off the curb and starts to cross) was 2.5 s for older pedestrians, compared with 1.9 s for younger ones (8). A study in Sweden (11) found that pedestri- ans aged 70 or older, when asked to cross an intersection very 7 Purpose Percent Walking for That Purpose Percent of all Modes Traveling for That Purpose Personal/Family Business 43 46 Social/Recreational 34 25 School/Church/Civic 14 9 Earning a Living 7 20 Other 2 0 Table 2. Purposes for pedestrian trips. (3)

fast, fast, or at normal speed, considered fast to be less than 4.3 ft/s (1.3 m/s). The comfortable speed was 2.2 ft/s (0.7 m/s) for 15 percent, well below the standard often used. A design walking speed of 3.3 ft/s (1.0 m/s) has been rec- ommended by Coffin and Morrall (12) at crossings used by large numbers of seniors, on the basis of their observations of speeds of older pedestrians at three types of crossings. Speeds were greater at unsignalized intersections than where there were signals. The older people in their study reported diffi- culty negotiating curbs and judging speeds of oncoming vehi- cles, as well as confusion with pedestrian walking signal indications (8). Results from other studies suggest that a design speed of 3.3 ft/s (1.0 m/s) may be too high. Pedestrians with Disabilities According to a study done in the United Kingdom in the 1980s, about 14 percent of individuals over 15 years of age had physical, sensory, or mental handicaps (13). This popu- lation has become much more mobile in recent decades, and increasing efforts have been made to meet their transporta- tion needs. As expected, the walking speeds for pedestrians with disabilities are lower than the average walking speed assumed for the design of pedestrian crosswalk signal timing (8). Table 4 shows some average walking speeds for those with various disabilities and assistive devices. Weather Conditions Walking speeds would likely be slowed even further under winter conditions resulting from snow and heavy footwear (14). The presence of snow, ice, or slush on sidewalks and roads leads to ill-defined curbs, hidden potholes and obsta- cles, greater amounts of glare and visual difficulties, and a greater chance of a slip or fall by a pedestrian (especially an older one) (8). All these conditions lead to reduced walking speeds during the winter (14). Pedestrians at Signalized Midblock Crossings A study of pedestrians with walking difficulty at pedestrian- actuated midblock signalized crossings on four-lane undi- vided roads found an average crossing speed of 4.2 ft/s (1.3 m/s) and a 15th percentile speed of 3.3 ft/s (1.0 m/s), equal to the design speed of 3.3 ft/s (1.0 m/s) recommended by Australian and U.S. design guides for sites with higher popu- lations of slower pedestrians (15). Table 5 summarizes crossing speeds for pedestrians with and without difficulty at midblock signalized crossing sites. Comparison of data in Tables 3 and 5 indicates that crossing speeds are higher at signalized intersections, possibly because of a perception of a less safe environment, especially as a result of turning vehicle conflicts (9). The authors noted that the results of all data for intersection and midblock crossing sites combined indicate that the design speed of 4.0 ft/s (1.2 m/s),commonly used for signal timing pur- poses, represents the 15th percentile crossing speed, with the cor- responding average crossing speed being 4.9 ft/s (1.5 m/s) (9). A similar Australian study that investigated pedestrian movement characteristics at pedestrian-actuated midblock signalized crossings on four-lane undivided roads found the 8 Average Speed, ft/s (m/s) Standard Deviation, ft/s (m/s) 15th Percentile, ft/s (m/s) 50th Percentile, ft/s (m/s) 85th Percentile, ft/s (m/s) Pedestrians with Walking Difficulty 4.42 (1.35) 0.25 (0.08) 3.74 (1.14) 4.23 (1.29) 5.34 (1.63) Pedestrians without Walking Difficulty 5.58 (1.70) 0.50 (0.15) 4.27 (1.31) 5.25 (1.60) 6.69 (2.04) All Pedestrians 5.35 (1.63) 0.48 (0.15) 4.07 (1.24) 5.12 (1.56) 6.43 (1.96) Table 3. Intersection crossing speeds of pedestrians with and without walking difficulty. (9) Disability or Assistive Device Mean Walking Speed, ft/s (m/s) Cane or Crutch 2.62 (0.80) Walker Wheel Chair 3.55 (1.08) 2.07 (0.63) Immobilized Knee 3.50 (1.07) Below Knee Amputee 2.46 (0.75) Above Knee Amputee 1.97 (0.60) Hip Arthritis 2.24 to 3.66 (0.68 to 1.16) Rheumatoid Arthritis (Knee) 2.46 (0.75) Table 4. Mean walking speeds for pedestrians with disabilities and users of various assistive devices. (8)

average crossing speed to be 4.7 ft/s (1.4 m/s) and the 15th per- centile speed to be 4.0 ft/s (1.2 m/s), very close to the general design speed of 4.0 ft/s (1.2 m/s) recommended by Australian and U.S. design guides. Pedestrian Start Loss and Clearance Time Gain Calculating start loss time and clearance time gain are important in determining a pedestrian’s effective green time, which is needed to model pedestrian performance measures (e.g., delay, queue length, and number of stops) (9). Start loss time is the time lag for stepping on the crossing after the Walk display begins. Clearance time gain is measured as the first part of the pedestrian clearance (Flashing Don’t Walk) inter- val when the pedestrian continues to step on and use the crossing (9). Table 6 summarizes pedestrian start loss and clearance time gain values for both intersection and midblock signalized crossing sites and shows similar findings to Table 3 in that start loss values are larger for intersection signalized crossings (possibly due, again, to a perception of a less safe environment) (9). Another study of pedestrians at midblock signalized cross- ing sites only found the average start loss to be 1.3 s and the average clearance time gain to be 2.9 s, pedestrian movement parameters close to the default values used in the SIDRA 1 software program (1 s and 3 s, respectively) (15). Varying Speeds During a Crossing One Australian study (15) concluded that pedestrian speeds for the first half of the crossing were higher than speeds in the second half, and the average and 15th percentile crossing speeds decrease with increased pedestrian flow rate. Also, crossing speeds and characteristics were similar during the weekdays and weekends. Pedestrian Space Requirements A recent study of pedestrian characteristics (16) recom- mends for standing area design a simplified body ellipse of 19.7 in by 23.6 in (50 cm by 60 cm), with a total area of 3.2 ft2 (0.3 m2), or roughly 108 percent of the ellipse suggested by Fruin’s 1971 study (17). This shape (see Figure 1) serves as an approximate equivalent to Fruin’s ellipse. This study also rec- ommends a body buffer zone of 8.6 ft2 (0.8 m2) for walking, near the upper end of the buffer zone range provided by Pushkarev and Zupan (18) and just before “unnatural shuf- fling” commences. Washington State’s Pedestrian Facilities Guidebook (4) states that two people walking side by side or passing each other while traveling in opposite directions take up an average space of 4.7 ft (1.4 m) with adequate buffer areas on either side (see Figures 2 and 3). The minimum width that best serves two pedestrians walking together or passing each other is 6 ft (1.8 m). 9 Average Speed, ft/s (m/s) Standard Deviation, ft/s (m/s) 15th Percentile, ft/s (m/s) 50th Percentile, ft/s (m/s) 85th Percentile, ft/s (m/s) Pedestrians with Walking Difficulty 4.23 (1.29) 0.28 (0.09) 3.28 (1.00) 4.30 (1.31) 4.99 (1.52) Pedestrians without Walking Difficulty 4.75 (1.45) 0.22 (0.07) 4.04 (1.23) 4.72 (1.44) 5.45 (1.66) All Pedestrians 4.66 (1.42) 0.24 (0.07) 3.87 (1.18) 4.66 (1.42) 5.41 (1.65) Table 5. Midblock crossing speeds of pedestrians with and without walking difficulty. (9) Start Loss Clearance Time Gain Average, s Standard Deviation Average, s Standard Deviation Clearance Time Gain Less Start Loss, s Intersection Signalized Crossing Sites All Weekdays Combined All Weekends Combined All Sites Combined 2.79 2.57 2.68 1.57 1.45 1.51 2.84 2.05 3.02 2.64 1.43 2.31 0.05 -0.52 0.35 Midblock Signalized Crossing Sites All Weekdays Combined All Weekends Combined All Sites Combined 1.35 1.27 1.30 0.57 0.53 0.55 2.75 3.08 2.93 2.38 2.17 2.25 1.40 1.80 1.60 Table 6. Comparison of pedestrian movement start loss and clearance time gain values for intersection and midblock signalized crossing sites. (9)

Spatial Bubbles A spatial bubble is the preferred distance of unobstructed forward vision while walking under various circumstances (4). Figure 4 illustrates the special bubbles that are comfort- able for the average pedestrian while attending a public event, shopping, walking under normal conditions, and walking for pleasure. Pedestrians with Disabilities Space requirements for pedestrians with disabilities vary considerably depending on their physical ability and the assistive devices they use. Spaces designed to accommodate 10 19.7 in (50 cm) Body Depth 23.6 in (60 cm) Shoulder Breadth Figure 1. Recommended pedestrian body ellipse dimensions for standing area (16). 4.7 ft (1.4 m) 8.7 ft (2.6 m) 12.7 ft (3.9 m) Figure 2. Spatial dimensions for pedestrians (4). Figure 3. Spatial needs for pedestrians with volume changes (4). Figure 4. Forward clear space needed by pedestrians (4).

wheelchair users are generally considered to be functional and advantageous for most people. Figure 5 illustrates the spatial dimensions for a wheelchair user, a person on crutches, and a person with visual impairments. Pedestrian Capacities Pedestrians are of all ages and abilities. Table 7 provides highly distinct walking characteristics and abilities for several different groups of pedestrians (6). Use of Signal Stages An Australian study found that most users (87 percent) crossed during the Walk interval, while the remaining pedes- trians crossed during the Flashing Don’t Walk or Steady Don’t Walk intervals (13 percent) (see Figure 6) (15). It appears that improper use of the crossing (crossing outside the Walk inter- val) and the decision not to use the crossing at all increases with increased pedestrian flow and decreases with increased vehicle flow (15). Pedestrian Waiting Periods The Florida Pedestrian Planning and Design Handbook (6) indicates that as a general rule, pedestrians are anxious to get back underway within 30 s. If waiting periods are longer, high school, college, and middle-aged adults, in particular, tend to look for a gap that they can use. In other cases, anticipating a long wait, the same pedestrians tend to cross in other non- signalized locations. The Florida Handbook also indicates that although it is not always practical to reward pedestrians with this short a wait, every effort should be made to keep the wait to the minimum. Pedestrian Crossing Choices In one study, researchers developed a model consistent with theoretical expectations of how pedestrians cross roads. The model contains variables descriptive of the street envi- ronment including continuous variables (such as roadside walking distance, crossing distance, and traffic volume) and discrete characteristics (such as the presence of marked cross- walks, traffic signals, and pedestrian signals) (19). The study (19) found that people are more likely to cross at an intersection with a traffic signal or a pedestrian signal head (Walk/Don’t Walk signs). Also, people are more likely to cross at any location with a marked crosswalk than at those with- out. As reflected by their coefficients in the model, the relative influences of these discrete characteristics vary among them- selves and across options. Specifically, the presence of a marked crosswalk is more influential at an intersection than at a midblock location. For crossings at an intersection, the most influential factors in descending order are pedestrian signals, marked crosswalks, and traffic signals. An increase in any continuous variable for a given option will result in a decrease in the probability of that option being chosen (i.e., the further a pedestrian has to walk to use a particular crossing option, the less likely it is that the pedestrian will choose that option). The magnitude of the decrease varies across these continuous variables and across options (19). 11 Figure 5. Spatial dimensions for people with disabilities (4).

12 Young Children At a young age, children have unique abilities and needs. Since children this age vary great in ability, it is important for parents to supervise and make decisions on when their child is ready for a new independent activity. Young children ■ Can be impulsive and unpredictable, ■ Have limited peripheral vision and sound source not located easily, ■ Have limited training and lack of experience, ■ Have poor gap/speed assessment, ■ Think grown-ups will look out for them, ■ Think close calls are fun, ■ Are short and hard to see, ■ Want to run and desire to limit crossing time, and ■ Like to copy the behavior of older people. Preteens By middle school years, children have many of their physical abilities but still lack experience and training. Now there is greater desire to take risk. Preteens ■ Lack experience, ■ Walk and bicycle more and at different times (higher exposure), ■ Ride more frequently under risky conditions (high traffic), ■ Lack positive role models, ■ Walk across more risky roadways (collectors and above), and ■ Are willing to take chances. High School Age By high school and college age, exposure changes and new risks are assumed. Many walk and bicycle under low-light conditions. High school children ■ Are very active and can go long distances and to new places; ■ Feel invincible; ■ Still lack experience and training; ■ Are capable of traveling at higher speeds; ■ Will overestimate their abilities on hills, curves, etc.; ■ Attempt to use bicycles and in-line skates based on practices carried over from youth; and ■ Are willing to experiment with alcohol and drugs. Novice Adults Adults who have not walked and bicycled regularly as children and who have not received training are ill-prepared to take on the challenges of an unfriendly urban environment. For novice adults, ■ 95 percent of adults are novice bicyclists, ■ Many are unskilled in urban walking, ■ Drinking can influence their abilities, ■ Many assume higher skills and abilities than they actually have, and ■ Most carry over sloppy habits from childhood. Table 7. Walking characteristics and abilities of different pedestrian groups. (6 ) Proficient Adults Proficient adults can be of any age. They are highly competent in traffic and capable of perceiving and dealing with risk in most circumstances. Some use bicycles for commuting and utilitarian trips, while others use bicycles primarily for recreation. Proficient adults ■ Comprise only 1 to 4 percent of the bicycling population in most communities, ■ Tend to be very vocal and interested in improving conditions, and ■ May be interested in serving as instructors and task force leaders. Senior Adults Senior adults, ages 60 and up, begin a gradual decline in physical and physiological performance, with a rapid decline after age 75. Many are incapable of surviving serious injuries. These changes affect their performance. For seniors, ■ They walk more in older years, especially for exercise/independence; ■ Many have reduced income and therefore no car; ■ All experience some reduction in vision, agility, balance, speed, and strength; ■ Some have further problems with hearing, extreme visual problems, and concentration; ■ Some tend to focus on only one object at a time; ■ All have greatly reduced abilities under low-light-night conditions; and ■ They may overestimate their abilities. Those with Disabilities Of those who live to an older age, 85 percent will have a permanent disability. Disabilities are common through all ages, and people with permanent disabilities constitute at least 15 percent of the population. Individuals with permanent physical disabilities, often kept away from society in the past, are now walking and bicycling regularly. Many others have temporary conditions, including pregnancy and broken or sprained limbs that may restrict their mobility. This group may include ■ Individuals with visual, hearing, mobility, mental/emotional, and/or other impairments; ■ Many older adults with reduced abilities; ■ Many who were previously institutionalized and are not trained to be pedestirians; and ■ Those dependent on alcohol or drugs, who may be hard to recognize.

concept of rules and why they are needed (until the age of about 10 years), and they often have problems with risk per- ception, attention, and impulsiveness that make them more vulnerable pedestrians. An observational study of children’s road crossing behav- ior at a signalized and nonsignalized intersection (20) found that well under half of the children who were observed looked in the direction of oncoming traffic before crossing. Slightly more than this looked while crossing and very few looked behind them (to check for turning vehicles) while crossing. A full visual search (looking in both directions before and while crossing and behind while crossing) was carried out by fewer than 5 percent of these observed and by none of the 8- to 12-year-old pedestrians at the signalized crossing. Children’s conceptions of safety are poorly formulated, and their schema for critical behaviors, such as crossing the street, are not well developed. The relatively high accident rate among young pedestrians also relates to the following factors (8): • Children have difficulty with – Seeing and evaluating the entire traffic situation cor- rectly as a result of their height – Information processing in peripheral vision and poorer visual acuity until about the age of 10 years – Distributing their attention and are easily preoccupied or distracted. – Discriminating between right and left – Correctly perceiving the direction of sound and the speed of vehicles – Understanding of the use of traffic control devices and crosswalks – Judging distances of cars and when a safe gap occurs between vehicles. • Many children believe that – The safest way to cross the street is to run – It is safe to cross against the red light. – Adults will always be kind to them, so drivers will be able to stop instantly if they are in danger 13 p g y g Ethnic/Cultural Diversity/Tourism America is rapidly becoming a nation with no clear majority population. All groups need access and mobility in order to fully participate in society. Transportation officials must pay close attention to communication, the creation of ethnic villages, and subcultural needs and practices. Most of these people depend heavily on walking and transit to get around. They include ■ Some newly arriving groups who lack urban experience and ■ Many who are used to different motorist behavior. Transportation Disadvantaged Thirty to forty percent of the population in most states does not have a car, often because they cannot afford to purchase or operate a car. These men, women, and children depend heavily on walking, transit, and bicycling for their basic freedom, access, and mobility. Table 7. (continued ) Figure 6. Use of signal stages by pedestrians at midblock signalized crossings (15). Using survey data (19), researchers calculated the prob- ability of the options being chosen in relation to each of the variables. The following are among the conclusions reached: • Increases in roadside distance (to an intersection) signifi- cantly affect a pedestrian’s choice to cross at an intersection. The decision to cross at an intersection is little affected, however, by increases in the crossing distance at that intersection. • Increases in crossing distance are twice as likely to affect jaywalking as increases in traffic volume. • Crossing midblock is little affected by any of the continu- ous variables. • Increases in roadside walking affect crossing at an intersec- tion many times more than crossing midblock. • Increases in traffic volume affect jaywalking more than crossing midblock. Child Pedestrians The characteristics of child pedestrians separate them from the adult pedestrian population and make them a particular concern for roadway designers. Children have a limited

Older Pedestrians The experiences of older pedestrians differ from those of the young. In general, older pedestrians do not behave as irra- tionally as do many children and young adults. However, older pedestrians often have physical conditions that limit their abil- ities to accurately assess the traffic situation. Older people also tend to walk more than others because they have more free time, and walking is good exercise and an inexpensive way to make short trips. The elderly are more law abiding than the general population, and they may, in fact, be too trusting of traffic signals and of drivers when it comes to crossing the streets. They are more likely than younger pedestrians to have accidents due to problems in information processing, judg- ment, and physical constraints. Other characteristics of older pedestrians follow (8): • Vision is affected in older people by decreased acuity and visual field, loss of contrast sensitivity, and slower horizon- tal eye movement. • They often have difficulty with balance and postural sta- bility, resulting in slower walking speeds and increased chances for tripping. • Selective attention mechanisms and multi-tasking skills become less effective with age, so older people may have difficulty locating task-relevant information in a complex environment. • They have difficulty in selecting safe crossing situations in continuously changing complex traffic situations, likely because of deficits in perception and cognitive abilities, as well as ineffectual visual scanning, limitations in time shar- ing, and inability to ignore irrelevant stimuli. • They have difficulty in assessing the speed of approach- ing vehicles, thus misjudging when it is safe to cross the road. • They have slower reaction time and decision making. • Those with arthritis may have restricted head and neck mobility as well as difficulty walking. • There is reduced agility for those who use canes or crutches for assistance. Pedestrian Delay Depending on the research, pedestrian delay can have dif- ferent definitions. Most of the studies reviewed defined delay as the amount of time between the point at which a pedestrian arrives at the curbside and the point at which he or she steps off the curb as well as any time that the pedes- trian has to wait in the roadway for acceptable gaps in the traffic. One major difficulty with this definition is deter- mining when a pedestrian “arrives” at the curbside. For instance, a pedestrian may walk straight to the curb and then look for a gap in the traffic or he/she may begin to watch for a gap long before stepping up to the curb. In the latter case, the pedestrian can adjust his or her walking speed in which to arrive at the curb at the instant a gap is available in the traffic. Although the pedestrian would experience the same delay as in the first case, the delay may not be counted in a research study. Another difficulty in determining pedestrian delay arises when pedestrians do not comply with street-crossing guide- lines. Pedestrian non-compliance occurs when pedestrians do not use a crosswalk to completely cross a street or when they use a crosswalk incorrectly, such as entering the crosswalk in front of an approaching vehicle. Although greater non- compliance increases the difficulty in determining pedestrian delay, greater pedestrian delay generally increases non- compliance. Most studies state that pedestrians become more likely to take extra risks at longer delays, i.e., above a delay of around 30 s, pedestrians are more likely to accept shorter gaps in traffic through which to cross (21, 22). The Highway Capacity Manual (HCM) (23) includes aver- age delay to pedestrians at unsignalized intersections as the measure of level of service (LOS) (see Table 8). The table was developed with anecdotal evidence that suggests delay to pedestrians at unsignalized intersections should be consid- ered congruent to delay to vehicles on the cross street at unsignalized intersections. The HCM LOS table for vehicles at two-way stop control is provided as Table 9. The HCM also provides a series of equations to calculate the average delay per pedestrian at an unsignalized intersection. The calculated 14 Level of Service Average Delay/Pedestrian (s) Likelihood of Risk-Taking Behavior* A < 5 Low B ≥ 5 – 10 C > 10 – 20 Moderate D > 20 – 30 E > 30 – 45 High F > 45 Very High * Likelihood of acceptance of short gaps. Table 8. HCM LOS criteria for pedestrians at unsignalized intersections. (23)

value is to be used in conjunction with Table 8 to determine the level of service of the intersection. Complicating matters is the belief that non-compliant pedestrians use several tactics when crossing streets. A 1998 FHWA report (24) cites a study by Song, Dunn, and Black where all street-crossing tactics were consolidated into four groups: double-gap, risk-taking, two-stage, and walk’n-look. Double-gappers look for an acceptable gap in the near lane as well as a gap twice as long in the far lane through which to cross in one continuous action. Slower or more cautious pedestrians often use this tactic. A pedestrian is said to employ the risk-taking tactic when he or she accepts the same size gap in each lane. Two-stage crossings involve pedestrians who cross one side of the street, take refuge in a median, and then cross the other side of the street. Finally, if a pedestrian does not initially see an acceptable gap in the traffic, he or she may walk down the side of the street while constantly looking for an acceptable gap through which to cross. This tactic is known as the walk’n-look and is perhaps the most efficient, greatly reducing or removing the delay to the pedestrian wishing to cross the street. However, it is not useful when the pedestrian’s main travel objective is perpendicular to the street. Pedestrian delay increases as vehicular traffic volumes increase. As pedestrian volumes increase, however, a prece- dent is established whereby motorists begin to expect pedes- trians. At these locations, drivers are more likely to yield to pedestrians, which in turn decreases pedestrian delay (25). 15 Level of Service Average Control Delay (s/veh) A B > 10-15 C > 15-25 D > 25-35 E > 35-50 F > 50 0-10 Table 9. HCM LOS criteria for two-way stop control (HCM Exhibit 17-2). (23)

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TRB's Transit Cooperative Research Program (TCRP) and National Cooperative Highway Research Program have jointly produced and published Improving Pedestrian Safety at Unsignalized Crossings. The product, which can be referred to as TCRP Report 112 or NCHRP Report 562, examines selected engineering treatments to improve safety for pedestrians crossing high-volume and high-speed roadways at unsignalized locations. The report presents the edited final report and Appendix A. TCRP Web-Only Document 30/NCHRP Web-Only Document 91 (Pedestrian Safety at Unsignalized Crossings: Appendices B to O) contains the remaining appendixes of the contractor's final report.

A summary of TCRP Report 112/NCHRP Report 562 as published in the July-August 2007 issue of the TR News is available online.

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