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Pedestrian Signal Safety - AAA Foundation for Traffic Safety

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For younger pedestrians, the mean walking speed (MWS) was 5.00 ft./sec. at traditional intersections<br />

and intersections equipped with PCD signals. As presented in Table F-3, there was no difference in<br />

the walking speed. The median walking speed was 4.90 ft./sec. at traditional intersections and PCD<br />

signals. The 15th-percentile walking speed represents the slower pedestrians at the intersection. The<br />

15th-percentile speed was similar at traditional signals and PCD signals. A walking speed of 4.00<br />

ft./sec. would accommodate the 15th-percentile younger pedestrian at any of these four intersections.<br />

For older pedestrians, MWS at PCD signals was 4.50 ft./sec., slightly faster than the MWS of 4.30<br />

ft./sec. at TPS. As presented in Table F-3, this difference was not significant at the 95-percent<br />

confidence level. The median walking speed was slightly faster at the countdown signal crossings.<br />

The 15th-percentile speed was also slightly faster at countdown signals (3.60 ft./sec.) compared to<br />

traditional signals (3.50 ft./sec.). A walking speed of 4.00 ft./sec. would accommodate the average<br />

older pedestrian at these intersections but would not accommodate the 15th-percentile older<br />

pedestrian.<br />

Table F-3. Significance testing of difference in mean walking speed at traditional and pedestrian<br />

countdown signals <strong>for</strong> two age groups.<br />

Subjects<br />

<strong>Pedestrian</strong>s<br />

under 65<br />

Intersection<br />

type<br />

Mean Standard<br />

deviation<br />

Traditional 5.0 1.05<br />

Countdown 5.0 1.01<br />

<strong>Pedestrian</strong>s Traditional 4.3 1.06<br />

65 and older<br />

Countdown 4.5 1.02<br />

Tcalc<br />

-0.199<br />

-1.272<br />

Outcome<br />

The difference between<br />

means is not significant<br />

at 95 percent.<br />

The difference between<br />

means is not significant<br />

at 95 percent.<br />

Table F-4 presents the results of significance testing of the difference in MWS <strong>for</strong> younger<br />

pedestrians and older pedestrians. As would be expected, the walking speed <strong>for</strong> older pedestrians<br />

was significantly slower than the walking speed <strong>for</strong> younger pedestrians, regardless of the type of<br />

pedestrian signal.<br />

Table F-4. Significance testing of difference in mean walking speed <strong>for</strong> younger pedestrians and older<br />

Intersection<br />

type<br />

Traditional<br />

Countdown<br />

Subjects Mean<br />

<strong>Pedestrian</strong>s<br />

under 65<br />

<strong>Pedestrian</strong>s 65<br />

and older<br />

<strong>Pedestrian</strong>s<br />

under 65<br />

<strong>Pedestrian</strong>s<br />

65 and older<br />

Standard<br />

deviation<br />

5.0 1.05<br />

4.3 1.06<br />

5.0 1.01<br />

4.5 1.02<br />

Tcalc<br />

5.631<br />

5.246<br />

Outcome<br />

The difference<br />

between means is<br />

significant at 95<br />

percent.<br />

The difference<br />

between means is<br />

significant at 95<br />

percent.<br />

181

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