Pedestrians have a wide range of needs and abilities. FHWA's Manual on Uniform Traffic Control Devices for Streets and Highways includes a walking speed of 4.0 ft/s (1.2 m/s) for calculating pedestrian clearance intervals for traffic signals. It also includes a comment that where pedestrians who walk slower than normal, or pedestrians who use wheelchairs, routinely use the crosswalk, a walking speed of less than 4.0 ft/s should be considered in determining the pedestrian clearance times. A 2005 TCRP-NCHRP study found a 15th percentile walking speed for young pedestrians of 3.77 ft/s (1.15 m/s) and a 15th percentile walking speed for older pedestrians of 3.03 ft/s (0.92 m/s). The study also determined that there is a statistical difference in walking speeds between older (older than 60 years) and younger (60 years and younger) pedestrians. Using population projections and the 15th percentile walking speeds for each population group more than 15 years old, the proportionally weighted 15th percentile walking speed for 2045 is 3.56 ft/s (1.09 m/s). Comparing the findings from the TCRP-NCHRP study with previous work results in the following recommendations: 3.5-ft/s (1.07-m/s) walking speed for timing of a traffic signal; if older pedestrians are a concern, then a 3.0-ft/s (0.9-m/s) walking speed should be used.
This study examined the effects of LED rectangular rapid-flash yellow beacons (RRFBs) in uncontrolled marked crosswalks in three experiments. In Experiment 1, the RRFB system was evaluated with a two- and a four-beacon system at four multilane crossings. Results showed a marked increase in motorist yielding behavior over the baseline for the two-beacon system and a small but statistically significant further increase with the four-beacon system. The second experiment compared a traditional pedestrian overhead yellow flashing beacon and a traditional side-mounted yellow flashing beacon with the RRFB system. The results showed that the traditional overhead and side-mounted yellow flashing beacons produced a minimal increase in yielding, whereas the RRFB system produced a marked increase in yielding behavior. A third experiment examined the effectiveness of the RRFB system at 19 sites in St. Petersburg, Florida, as well as three additional sites, two in the suburbs of Chicago, Illinois, and one in the Washington, D.C., area. Results indicated that baseline daytime yielding behavior increased from an average of 2% to 86% at the 19 St. Petersburg sites and was 85% at the 2-year follow-up. A time-series intervention regression modeling was employed that estimated the parameters of the model based on a double bootstrap methodology. The results of this analysis confirmed a highly significant level change following the introduction of the RRFB that showed no sign of decay over time. Similar results were obtained at the District of Columbia and Chicago suburb sites. Probe data collected after dark revealed an even larger effect with yielding levels at the middle to high 90% level.
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