Click for next page ( 12


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

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

OCR for page 11
12 Table 7. Walking characteristics and abilities of different pedestrian groups. (6 ) 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. 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.