Designing for Special Pedestrian Populations

Special pedestrian populations include young children, senior citizens, and disabled pedestrians of all ages. Each special pedestrian population has their own unique set of characteristics that limit their ability to safely travel across and along roadways. For example, young children do not have the maturity and understanding — or various other cognitive abilities — to understand how to share the roadway with automobiles and how to safely cross streets. Older pedestrians are not as mobile as younger adults and/or may have limited hearing or vision. Physical disabilities may include no or limited vision, or the need to use wheelchair, walkers, or other mobility assistance devices.

Designing for pedestrians with physical disabilities

An estimated 85 percent of Americans living to full life expectancy will experience some sort of permanent disability sometime in their lifetime. The Americans With Disabilities Act (ADA) has paved the way for some significant improvements for the 43 million Americans who are disabled. Signed into law on July 26, 1990, the ADA was a landmark in civil rights legislation, mandating that disabled persons have full access to all public facilities in the United States.

"One-fifth of the people in this country currently have a disability. When we build something improperly, we're leaving that one-fifth out," notes Barbara McMillen, Transportation Specialist with the FHWA. "Accessibility, project development, and construction must all come together. It's a safety issue. We need to make pedestrian facilities more usable for everyone."

Design elements that deserve special consideration for pedestrians with disabilities include:

  • Wheelchair ramp placement and design (ramp slope, side-slope, level landing, crosswalk placement, detectable warning, smooth transitions, etc)
  • Clear sidewalk width
  • Sidewalk cross-slope
  • Street furniture design and placement
  • Tactile warning strips at street crossings
  • Audible pedestrian signals (for information on accessible pedestrian signals, visit the Accessible Pedestrian Signal web site)
  • Pedestrian crossing time
  • Construction zones and temporary work zones
  • Other pedestrian features

In response to the ADA and the Transportation Equity Act for the 21st Century (TEA-21), the U.S. Department of Transportation has drafted a policy statement calling for measures that will serve to develop a transportation infrastructure that provides access for all, a real choice of modes, and safety in equal measure for each mode of travel. The US Department of Transportation and the US Access Board have developed a range of technical assistance materials to assist practitioners in meeting the requirements of the ADA and other accessibility laws.

US Access Board

USDOT

Designing for older pedestrians

Many older and disabled pedestrians remain active and busy, and often travel by public transit to work, shop, or for recreational purposes. All of these trips typically involve walking for at least some part of the trip. At times, traveling on foot to the other side of a busy street can become dangerous. Problems can result from wide streets, traffic signals with insufficient crossing time, lack of convenient or safe crossing opportunities, high speed or high volume traffic, and drivers focusing their attention on other vehicles instead of pedestrians.

More Americans are living longer—to an average age of 77 years—thanks to advances in health care, nutrition, and a better quality of life. Currently, older Americans represent 13 percent of the U.S. population. By 2030, there will be about 70 million older persons living in the United States. The AARP notes that the older population will balloon between 2010 and 2030, when the baby boom generation reaches the age of 65. The number of Americans aged 80 or over will rise sharply, from 61 million in 1995 to 320 million in 2050 and 1,055 million in 2150. These demographic changes will greatly change the course of pedestrian design, as design elements such as street crossing times, will react to market forces.

The situation can be grim for older persons who become unable to drive. Streets have become less friendly to seniors and other pedestrians. As frailty increases with age, citizens over the age of 65 continue to have the highest pedestrian fatality rates. If public transit is not reliable and streets are not easy or safe to cross and walk along, many seniors who do not drive must depend on families, neighbors, friends, or taxi services for rides—or they must remain homebound.

Effects of aging

In general, the aging process causes a deterioration of physical, cognitive, and sensory abilities. According to researchers at the Federal Highway Administration (FHWA), National Highway Traffic Safety Administration (NHTSA), and the University of North Carolina Highway Safety Research Center (UNC-HSRC), problems experienced by older pedestrians can include in varying degree:

  • Decreased visual acuity, poor central vision, reduced ability to scan the environment
  • A reduced range of joint mobility
  • Reduced ability to detect and localize different sounds
  • Reduced endurance
  • Reduced tolerance for extreme temperature and environment
  • Decreased agility, balance, and stability
  • Inability to quickly avoid dangerous situations
  • Slower reflexes
  • Excessive trust that other motorists will obey traffic laws
  • Impaired judgment, confidence, and decision making abilities

What's more, seniors are more likely to experience restrictive disabilities than other age groups. In 1994 and 1995, 52.5 percent of seniors reported having one or more disabling conditions. Nearly three quarters of the over-80 population report having one or more disabilities.

What can be done?

It's the city's job to provide reliable public transportation and well-lit streets with good walkways and safe, sheltered benches to rest. Planning measures should be taken to prevent highways from dividing commercial spaces from residential spaces. While these measures take time, designers and engineers can react more immediately to the pedestrian design needs of senior citizens by:

  • Using technology to extend crossing times at traffic signals. In Los Angeles, CA and Portland, OR, engineers use microwave technology to detect the presence of persons who are moving too slowly to finish crossing the street. The detector will automatically extend the crossing time for several more seconds, allowing the pedestrian to finish crossing safely.
  • Tightening curb radii, which prevents vehicles from rounding corners at high speeds.
  • Providing adequate medians so that pedestrians can feel comfortable when crossing a wide street.
  • Changing the pedestrian signal timing calculations for the walking clearance interval from a speed of 4.0 ft/s (1.22 m/s). This speed represents the average time for a typical person to cross the street. Recognizing the slower gait and shorter stride of older people, as well as the slower travel speeds for disabled pedestrians, the FHWA and the USDOT recommended in the Older Driver Highway Design Handbook" that pedestrian signal timing be based on a walking speed of 2.8 ft/s (0.85 m/s). They also recommend the installation of signs to explain precisely what the various crosswalk signal displays mean.

Even small design and engineering improvements can make a big difference.

Purpose

  • Assure that all sidewalks and street crossings accommodate older and disabled pedestrians and are in compliance with ADA accessibility requirements

Considerations

  • Accommodating the needs of older and disabled pedestrians will assure that the sidewalks and crossings are accessible to all other users such as people with carts and people pushing strollers.
  • Traffic signals that have concentrations of older or disabled pedestrian populations should be evaluated for extra crossing and clearance times and accessible pedestrian signals.
  • All communities should have implementation plans to retrofit their infrastructure to comply with ADA requirements.
  • Most ADA sidewalk or crossing features cost very little more to build into new projects, but can be expensive to retrofit, such as wheelchair ramps.

Estimated cost

  • Retrofitting a wheelchair ramp may cost about $1,000 to $2000 for each corner.
  • Audible pedestrian signals cost $400 to $800 per corner per crossing.