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46 4.50 4.00 Walking Speed (ft/s) 3.50 3.00 2.50 2.00 1.50 1.00 0.50 0.00 1950 all ages (58) 1950 older (58) 1998 Guerrier, younger (60) Dahlstedt, older (11) 2001 Akcelik, w/walking difficulties, 1998 Guerrier, older (60) 1982 Engineering Handbook (59) 1982 Engineering Handbook (59) 2001 Bennett, w/walking difficulties, 2001 Bennett, w/walking difficulties, 2001 Bennett, w/o walking difficulties, 2001 Bennett, w/o walking difficulties, 1993 data, Knoblauch, younger, design 2001 Bennett, for design (9) 2004 LA, problem intersections (58) 2003 data, Fitzpatrick, older, 106 data 2003 data, Fitzpatrick, younger, 2,335 1995 Coffin, older, midblock (12) 1993 data, Knoblauch, older, 2,378 data 2001 Older Pedestrian Handbook, less 2001 Traffic Control Devices Handbook 1993 data, Knoblauch, older, design (14) 1993 data, Knoblauch, younger, 2,081 1995 Coffin, older, intersection (12) midblock signal (64) midblock signal (9) midblock signal (9) intersection (9) data points (14) intersection (9) data points capable (63) points (14) points (62) (14) Figure 23. Comparison of findings from previous studies for 15th percentile walking speed (labels contain year of study or year data were collected if known, authors or abbreviation of title, characteristics of study if relevant, and reference number in parentheses). Conclusions as required by law). This section also describes an analysis of street and traffic characteristics (e.g., speed limit, number of Comparing the findings from this TCRP/NCHRP study with lanes, and traffic volumes) that influence motorist compliance previous work resulted in the following recommendations: at marked crosswalks at unsignalized intersections. More details are included in Appendix M. · 3.5 ft/s (1.1 m/s) walking speed for the general population; and · If older pedestrians are a concern, use a 3.0 ft/s (0.9 m/s) Summary of Motorist Yielding Rates walking speed. Tables 21 and 22 summarize the measured motorist yield- ing data from both types of pedestrian crossings (general Motorist Compliance population and staged), including comparable evaluation This section presents the study findings on the effectiveness data from the literature where available. The results are of pedestrian crossing treatments at unsignalized intersections grouped into the three basic categories of pedestrian crossing as measured by motorist compliance (yielding or stopping treatments used in the study. The range column in the table Table 20. Walking speed by age groups for Knoblauch et al. and TCRP/NCHRP studies. Age Group Walking Speed (ft/s) Knoblauch et al. TCRP/NCHRP th Sample 15 50th Sample 15th 50th Size Percentile Percentile Size Percentile Percentile Young 2081 4.02 4.79 2335 3.77 4.74 Old 2378 3.10 3.94 106 3.03 4.25 All 4459* 3.53* 4.34* 2441 3.70 4.72 *Calculated using values provided in Knoblauch et al. paper (14).
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47 Table 21. Summary of motorist yielding compliance from three sources for red signal or beacon and active when present. TCRP D-08/NCHRP 3-71 Study Other Studies Compliance Staged Compliance General Compliance Literature Pedestrian Crossing Population Pedestrian Review (from Table L-1) Crossing Crossing # of Range Average # of Range Average # of Range Average Treatment Sites (%) (%) Sites (%) (%) Sites (%) (%) Red Signal or Beacon Midblock Signal 2 97 to 99% 4 91 to 95% NA NA NA 100 98 Half Signal 6 94 to 97% 6 96 to 98% 1 99 99% 100 100 HAWK Signal 5 94 to 97% 5 98 to 99% 1 93 93% Beacon 100 100 Active When Present In-Roadway NA NA NA NA NA NA 11 8 to 66% Warning Lights 100 Overhead 3 29 to 47% 4 38 to 49% 10 13 to 52% Flashing Beacon 73 62 91 (Pushbutton Activation) Overhead 3 25 to 31% 3 61 to 67% NA NA 74% Flashing Beacon 43 73 (Passive Activation) Pedestrian 6 46 to 65% 4 72 to 74% NA NA NA Crossing Flags 79 80 Notes: "NA" indicates that data were not collected or available in the literature. The "Range" column represents the range of motorist yielding for all sites with the treatment. The "Average" column represents the average value of motorist yielding for all sites with the treatment. Table 22. Summary of motorist yielding compliance from three sources for enhanced and/or high-visibility treatments. TCRP D-08/NCHRP 3-71 Study Other Studies Compliance Staged Compliance General Compliance Pedestrian Crossing Population Pedestrian Literature Review (from Crossing Table L-1) Crossing # of Range Average # of Range Average # of Range Average Treatment Sites (%) (%) Sites (%) (%) Sites (%) (%) Enhanced and/or High-Visibility In-Street Crossing Signs (25 to 30 mph 82 to 84 to 44 to 3 87% 3 90% 7 77% [40 to 91 97 97 48 km/h] Speed Limit) High-Visibility Signs and Markings 10 to 2 17% 2 4 to 35 20% NA NA NA (35 mph 24 [55 km/h] Speed Limit) High-Visibility Signs and Markings 1 61 61% 1 91 91% 1 52 52% (25 mph [40 km/h] Speed Limit) Median 6 7 to 75 34% 7 7 to 54 29% NA NA NA Refuge Islands Notes: "NA" indicates that data were not collected or available in the literature. The "Range" column represents the range of motorist yielding for all sites with the treatment. The "Average" column represents the average value of motorist yielding for all sites with the treatment.
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48 represents the range of average compliance values for the sites compliance rates as shown in Tables 21 and 22. The with that treatment. If a site had less than 10 general popula- research team concluded that other factors (e.g., traffic tion pedestrians crossing the street during data collection, the volume, roadway width, and street environment) were compliance values were not included in summary statistics. affecting compliance rates. These factors are discussed in The average column represents the average compliance rate more detail in Appendix L. for all sites with that treatment. The research team prepared these findings from Tables 21 and 22: Significant Differences in Treatment Effectiveness · The motorist compliance rates for staged pedestrians and As indicated in the previous section, many crossing treat- general population pedestrians were in relatively close ments had wide ranges in the measured compliance rate (see agreement for most crossing treatments. Only two crossing Figure 24). Thus, even though the average compliance may treatments (total of four study sites) had motorist yielding be greater for some treatments, the wide range in compliance rates with a greater than 10 percent difference between does not mean that one treatment is statistically more effec- general population and staged pedestrians. At three Los tive than others. The research team tested statistical differ- Angeles sites, the research team attributed the differences ences of compliance rates between the crossing treatments to general population pedestrians who routinely stepped using two different methods: off the curb while waiting, whereas staged pedestrians did not step off the curb until motorists yielded. At a single · Analysis of variance--determines whether the mean com- Tucson site, the general population pedestrian flow was pliance rates of the crossing treatments are statistically dif- fairly heavy, which could lead to two possible explanations: ferent and (1) motorists were more likely to yield to larger groups · Multiple comparisons test--uses Tukey's "honestly signif- of pedestrians than the single staged pedestrian and (2) the icant differences" (HSD) test to find out which crossing larger groups of pedestrians could have been more treatments have statistically similar mean compliance assertive in claiming the crosswalk right-of-way. Because rates. the behavior of the staged pedestrians was consistent among all sites, these compliance rates are used in further analyses. The findings of the statistical analyses are summarized as · Red signal or beacon treatments consistently perform well, follows: with compliance rates above 94 percent. The research team concluded that these treatments are effective because they · The three devices designated as red signal or beacon had send a clear regulatory message (a red signal means "Stop") statistically similar mean compliance rates. These devices to motorists that they must stop for pedestrians. Nearly all include the midblock signal, half signal, and HAWK signal the red signal or beacon treatments evaluated were used on beacon. All three devices had average compliance rates busy, high-speed arterial streets. greater than 97 percent. These statistical results validate the · Pedestrian crossing flags and in-street crossing signs also research team's approach of grouping these devices into the were effective in prompting motorist yielding, achieving 65 same "red signal or beacon" category. and 87 percent compliance, respectively. However, many of · Many crossing treatments in the "active when present" and these crossing treatments were installed on lower-volume, "enhanced and/or high-visibility" categories had compli- two-lane roadways. It has been suggested that motorists are ance rates that were not statistically different than other more likely to yield to pedestrians crossing narrow, low- treatments. Only three treatments were statistically differ- volume and low-speed roadways. This is supported by the ent from others in these categories. The compliance rate for difference in compliance for high-visibility signs and in-street crossing signs was statistically different than com- markings. On streets with a 35-mph (55-km/h) speed pliance rates for high-visibility signs and markings and limit, the average compliance rate was 17 percent; however, overhead flashing beacons (pushbutton activation). The on streets with a 25-mph (40-km/h) limit, the average research team concluded that it may still be appropriate to compliance rate was 61 percent (although only a single site differentiate between the "active when present" and had this speed limit). "enhanced and/or high-visibility" treatments when dis- · The measured compliance rates for many crossing treat- cussing function. However, the statistical results indicated ments varied considerably among sites. For example, that nearly all treatments in these two categories did not treatments in the "active when present" and "enhanced have statistically significant differences between the mean and/or high-visibility" categories have a wide range of compliance rates.
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49 100% 90% 80% 70% Motorist Yielding (%) 60% 50% 40% 30% 20% Maximum site value Average of all sites 10% Minimum site value 0% Msig Half Hawk InSt Flag OfPb Refu HiVi OfPa Treatment Type Abbreviations: Msig=midblock signal; Half=half signal; Hawk=HAWK signal beacon; InSt=in- street crossing signs; Flag=pedestrian crossing flags; OfPb=overhead flashing beacons (pushbutton activation); Refu=median refuge island; HiVi=high-visibility signs and markings; OfPa=overhead flashing beacons (passive activation) Figure 24. Site average and range for motorist yielding by crossing treatment. Street Characteristics That Influence Pedestrian crossing flags did not show a statistically differ- Treatment Effectiveness ent mean compliance for locations with a different number of lanes. The flags on two-, four-, and six-lane highways had sta- Because of the wide range in measured compliance rates tistically similar compliance rates. Median refuge islands were among sites, the research team hypothesized that other vari- the only treatment with statistically different compliance val- ables were influencing the treatment effectiveness. For exam- ues based on the number of lanes. ple, an in-street crossing sign installed on a wide, high-speed The bottom chart in Figure 25 regroups the data in the arterial would likely produce a lower compliance rate than if top chart of Figure 25 by number of lanes. As seen in the installed on a narrow, lower-speed collector street. The bottom chart of Figure 25 for four-lane highways, the red research team performed a qualitative analysis and a statisti- devices have a much higher compliance rate than the other cal analysis of covariance to find those factors that most non-red devices. All but one of the devices on a two-lane affected the range in compliance rates. roadway performed at better than a 60-percent compliance rate. Effect of Number of Lanes The statistical analysis of covariance also indicated that the number of lanes crossed was a statistically significant variable The top chart in Figure 25 shows the motorist yielding by (at the 0.05 level) in predicting motorist yielding at treatments. treatment type (major grouping) and number of lanes. For the "red signal or beacon" devices, the number of lanes did not affect performance. Within the study set, red devices were on Effect of Speed Limit two-, four-, and six-lane roadways. A compliance rate above 94 percent exists, regardless of the number of lanes on the facil- Figure 26 shows motorist yielding by treatment type and ity. The half signal treatment had statistically the same com- speed limit.As seen in the top chart of Figure 26, in-street pedes- pliance rate for both two and four lanes. The same result was trian crossing signs and overhead flashing beacons (pushbutton true for the HAWK treatment on four- and six-lane roads. activation) appear to have an increase in compliance with an
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50 Grouped by Treatment Type 100% 90% 80% 70% Motorist Yielding (%) 60% 50% 40% 30% 20% Maximum site value Average of all sites 10% Minimum site value 0% OfPa (2) OfPa (4) OfPb (4) HiVi (4) Msig (4) Flag (2) Flag (4) Flag (6) Hawk (4) Hawk (6) Refu (2) Refu (4) Half (2) Half (4) InSt (2) Treatment Type (Number of Lanes) Grouped by Number of Lanes 100% 90% 80% 70% Motorist Yielding (%) 60% 50% 40% 30% 20% Maximum site value Average of all sites 10% Minimum site value 0% OfPa (2) OfPa (4) OfPb (4) Flag (2) Flag (4) Flag (6) HiVi (4) Msig (4) Refu (2) Refu (4) Hawk (4) Hawk (6) Half (2) Half (4) InSt (2) Treatment Type (Number of Lanes) Abbreviations: Msig=midblock signal; Half=half signal; Hawk=HAWK signal beacon; InSt=in-street crossing signs; Flag=pedestrian crossing flags; OfPb=overhead flashing beacons (pushbutton activation); Refu=median refuge island; HiVi=high-visibility signs and markings; OfPa=overhead flashing beacons (passive activation) Figure 25. Motorist yielding by crossing treatment and number of lanes.
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51 Grouped by Treatment Type 100% 90% 80% 70% Motorist Yielding (%) 60% 50% 40% 30% Maximum site value 20% Average of all sites 10% Minimum site value 0% HiVi (25) HiVi (35) Half (35) OfPa (30) OfPa (35) Msig (35) Flag (25) Flag (30) Flag (35) InSt (25 ) InSt (30 ) OfPb (30) OfPb (35) Refu (25) Refu (30) Refu (35) Hawk (35) Hawk (40) Treatment Type (Speed Limit) Grouped by Speed Limit 100% 90% 80% 70% Motorist Yielding (%) 60% 50% 40% 30% 20% Maximum site value Average of all sites 10% Minimum site value 0% OfPa (30) OfPa (35) OfPb (30) OfPb (35) HiVi (25) HiVi (35) Refu (25) Refu (30) Refu (35) Hawk (35) Hawk (40) Msig (35) Half (35) Flag (25) Flag (30) Flag (35) InSt (25) InSt (30) Treatment Type (Speed Limit) Abbreviations: Msig=midblock signal; Half=half signal; Hawk=HAWK signal beacon; InSt=in-street crossing signs; Flag=pedestrian crossing flags; OfPb=overhead flashing beacons (pushbutton activation); Refu=median refuge island; HiVi=high-visibility signs and markings; OfPa=overhead flashing beacons (passive activation) Figure 26. Motorist yielding by crossing treatment and posted speed limit.