Pedestrian walking speeds and start-up times are important in roadway design. Transportation designers need to know the amount
of time required for pedestrians of all ages and abilities to cross roadways safely. Researchers have found that older pedestrians cross more slowly than younger pedestrians; and within both age groups, women walk more slowly than men. The same relationships are found in start-up times. Moreover, those who comply with traffic or pedestrian signals cross more slowly than noncompliers, and these complier statistics should be the basis for crossing signal design.

PURPOSE AND OBJECTIVES OF THE RESEARCH

Richard L. Knoblauch, Martin T. Pietrucha, and Marsha Nitzburg reported their research in "Field Studies of Pedestrian Walking Speed and Start-Up Time." The paper appeared in the Transportation Research Board's Transportation Research Record No. 1538, Pedestrian and Bicycle Research, published in 1996.

With the proportion of people over the age of 65 increasing in North America, research regarding drivers in this age group has also increased. Little has been studied, however, about older pedestrian behavior.

Walking speed is one factor in pedestrian studies; another is the start-up time, or the time from illumination of the Walk signal until the person steps off the curb. In one study of people age 70 or older, the normal walking speed for 90 percent of the group was less than four feet per second. The Manual on Uniform Traffic Control Devices (MUTCD) suggests four feet per second as a normal walking speed, a speed that perhaps as many as 30 percent of the population cannot achieve. The Traffic Control Devices Handbook (TCDH) confirms the slow walking speed of many pedestrians and emphasizes that, once people enter an intersection, they have "the moral and legal right to complete the crossing."

Other findings support estimating elderly pedestrian speeds at 2.5 to 3.25 feet/sec. Various factors may influence walking speeds, such as terrain or slope, vehicle density and speed, and the number of pedestrians at a crossing. No studies have been done on the abilities of the elderly in crowds. Since little information was available, this research was conducted to measure the walking speed and start-up time of pedestrians by age and environmental condition.

METHOD

The researchers selected 16 signal-controlled crosswalks in four urban areas: Richmond, Virginia; Washington, D.C.; Baltimore, Maryland; and Buffalo, New York. During each eight-hour observation period at the crosswalks, they monitored a minimum of 26 to 30 pedestrians over 65 years of age and recorded these types of site-specific information:

The weather conditions studied, during daylight hours on weekdays, were:

• dry roads and sidewalk,
• light to moderate rain with wet roads and curbs, and
• snow in the air, on the road or sidewalk, or both.

The wind intensity was estimated.

The pedestrians studied all appeared to be at least 65 years old, with a control group of people under age 65. The ability of observers to estimate age was tested with a random pedestrian sample; the only error was a 62-year-old man whom all five observers thought was at least 68 years old.

Observers disregarded persons carrying or pushing items; holding hands or assisting others; using quadpod canes, walkers, or wheelchairs; or walking with bikes or dogs. Also not included were people crossing diagonally, stopping at the median, running when entering the crosswalk, stepping into the roadway before starting to cross, waiting for traffic during crossing, or entering or exiting the street more than four feet outside the crosswalk.

The observers noted gender, whether the person was walking alone or in a group, the group size (a group consisted of two or more pedestrians crossing the road at the same time, whether acquainted or not), whether pedestrians stayed inside the crosswalk, whether they obeyed traffic signals, and the location of pedestrians at the time the signals changed.

Other recorded behaviors were:

Crossings were measured with a hand-held, digital, electronic stopwatch that was started as pedestrians left the curb and stopped when they stepped up on the opposite curb. Start-up times were measured at crossings with a pedestrian signal. Comparison tests were made to be sure that all observers were following the timing procedure similarly.

RESULTS

Pedestrian Walking Speeds

Of the 7,123 pedestrians observed, 3,665 were 65 or older. Some of the findings were:

• The average walking speed for older pedestrians was 4.11 feet per second, compared with 4.95 for younger pedestrians.

• Older females had the slowest walking speed at 3.89 feet per second.

• The difference in speed between older men and older women was .42 feet per second; the difference between younger men and younger women was .32.

• Those who started crossing on the Walk signal were slower than those who crossed on the flashing or steady Don't Walk signals.

• Contrary to the findings of some other studies, it appeared that some pedestrians understood the difference between the flashing Don't Walk signal (the clearance phase) and the steady Don't Walk signal.

• At sites without pedestrian signals, those who started to cross on the green light tended to walk more slowly than those who crossed on the red.

• Locations with longer signal cycles had faster crossing speeds.

• Shorter pedestrian signal times were associated with faster crossing speeds. The researchers did not know whether this was because pedestrians knew that the crossing times were short or because shorter crossing times occurred in places where pedestrians walk more quickly.

Pedestrians who complied with crossing signals (62 percent of the total observed or 4,460 people) walked more slowly than those who crossed illegally. Older "compliers" averaged 3.94 feet per second, compared with the total average for older pedestrians of 4.11. Younger compliers averaged 4.79 feet per second, compared with their total average of 4.95.

Some findings on the effect of site and environmental factors were:

• Older females walked 0.4 feet per second slower than older males, as compared with a difference of 0.32 feet per second between younger females and males.

• Pedestrians who started or ended outside the crosswalks walked faster than those who remained within the crosswalks.

• Compliers who crossed where there were pedestrian signals walked at the same speed as compliers who had only traffic signals.

• Single compliers walked faster than groups of compliers.

• Older pedestrians walked more slowly when it was snowing.

• Longer cycle lengths seemed to relate to faster walking times.

• Compliers walked faster where there were short, steady Walk and short, flashing Walk intervals.

• Longer, steady Don't Walk intervals seemed to relate to slower walking times.

The research indicated that complier walking speeds are a better basis for signal design than the speeds of those who cross illegally. Using 15th percentile values (85 percent walked at this speed or faster), a speed of three feet per second for older pedestrians seems appropriate for design purposes.

Pedestrian Start-up Times

Because start-up times could be observed only for those who waited for the signal to allow them to cross, these pedestrians are compliers by definition. The researchers found that the only site or environmental factor that significantly related to walking speed was street width. For most factors, start-up times were significantly longer for older pedestrians than younger pedestrians. Start-up times were almost identical for both age groups whether walking alone or in a group.