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90 However, the analysis also suggests that pedestrian confi- then asked to estimate the likelihood of their being involved dence was increased with some of the crossing treatments, in a crash. Especially when participants have control over even where an effect was not hypothesized. Most notably, the behavior that could result in an adverse event (as they did in installation of the raised crosswalk and flashing beacon treat- the present research), they are likely to underestimate their ments resulted in an increase in the rates of opportunity uti- risk of being involved in the adverse event. They believe that lization, P(GO|Y) and P(GO|CG). At the same time, the they are better than average at the skills necessary to avoid the two-lane roundabout RCW treatment also contributed to an adverse event. The high confidence ratings in the present increase in the number of forced yields, defined as the pedes- research, despite the relatively high risk, could be an example trian stepping into the roadway before a yield was initiated of this phenomenon that has been documented for individu- by the driver. A similar increase in the willingness of sighted als having unimpaired vision. pedestrians to accept risk was observed in a field study of two Perhaps even more to the point, estimates of cumulative different pedestrian crossing treatments (Schroeder 2008). In risk have been found to be especially skewed toward over- observational before-and-after studies with in-road pedestrian estimation of safety (Knauper et al. 2005). Thus an individual warning signs and in-pavement pedestrian-actuated flashing who actually required experimenter intervention on only one beacons, the author noted a decrease in pedestrian critical gap of 20 crossings may nonetheless have decided during subjec- after treatment installation. It was hypothesized that pedes- tive questions that he or she would feel comfortable making trians felt "empowered" or at least more noticeable with the the crossing in the future because there may have been no treatment in place, which effectively lowered their perceived realization that that was a very high rate--an average likeli- risk threshold. hood of one risky crossing every 2 weeks if the individual These trends raise the question of whether the apparent commuted back and forth across the crossing daily. Research increase in confidence is desirable. Clearly, more forced yields by Ayers et al. (1998) provides further insight into why con- would be a concern if the driver had not paid attention. On fidence in crossing safety was much higher than warranted the other hand, even with higher opportunity utilization and by the number of interventions. These researchers found that more forced yields, the rate of interventions decreased. risk perception may not play as dominant a role in common behavioral choice as perception of whether an action can be completed successfully. Having completed a number of appar- Self-Assessment of Risk and Travel Skills ently successful crossings, participants may simply have ignored The apparent increase in confidence is also reflected in the interventions or other indications of their risky decisions and post-experiment participant questionnaires, where participants based their ratings of crossing safety simply on the fact that responded positively to a question regarding their confidence they had made a number of safe crossings. in crossing safely, both in the pretest and posttest, and to the To understand the implications of the present research, in treatments. Across all settings, participants' ratings of confi- which most participants felt quite confident that they could dence in crossing safely, both before and after treatments, were safely cross at roundabouts and channelized turn lanes quite high (a range of 3.66 to 4.83 on a scale of 1, low confi- despite average performance data to the contrary, one must dence to 5, high confidence). However, the range of interven- recognize that overestimation of safety is a common occur- tions across all sites and with or without treatment was also rence. Therefore the objective measure of safety--that is, large, from 0.5% to 9.4%. This raises questions about the rela- interventions--is the most reliable (available) indication of tionship between (stated) confidence in decision-making and crossing safety at roundabouts and channelized turn lanes. the quality of these decisions. One should not be misled into thinking that crossings at these It is quite likely that participants often failed to recognize locations are safe because participants perceived them to be. when they made risky crossings. On many crossings, partici- pants may have been unaware of the extraordinary avoidance Viability of Interventions as maneuvers of drivers, or of how close they came to a crash. a Measure of Risk The O&M specialist gave participants no feedback regarding crossings, many of which were quite risky but nonetheless did The accessibility framework applied in this research ulti- not result in interventions because the O&M specialist could mately focuses on the concepts of pedestrian delay and risk. see that drivers were taking avoidance action. There is a large Pedestrian delay is reliably and objectively measured. The mea- body of research indicating that people tend to underestimate surement of pedestrian risk is more challenging. The tradition- the likelihood that they will be involved in an adverse event, ally used objective measure of risk in the transportation field is reviewed in Greening and Chandler (1997). In the typical par- the frequency and rate of collisions. Clearly, crash statistics are adigm for this research, participants are told the average rate not applicable given the experimental design used, and conse- of occurrence of a given adverse event, such as a crash, and are quently other surrogate safety measures need to be identified.