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20 evaluate the feasibility of a pavement treatment designed to have potential in improving specific aspects of pedestrian alert blind pedestrians when vehicles have yielded to them. accessibility. In the base condition, it is assumed that the sites The second study examined drivers' yielding behavior at a meet current design and basic accessibility standards, includ- two-lane roundabout, along with an evaluation of the effec- ing appropriate curb ramps, detectable warnings, and marked tiveness of the roadway treatment identical to that used on the crosswalks. Under these baseline conditions, it is recognized closed course study. In the first study, there were two experi- that sighted pedestrians likely have better yield- and gap- mental conditions: a control condition and a treatment con- detection capabilities and that delay and risk are higher for dition in which devices similar to rumble strips were placed blind pedestrians. However, any treatment tested is hypoth- on the roadway surface. Seven individuals with severe visual esized to also improve crossing conditions for sighted pedes- impairments participated. Participants stood at a crosswalk trians, and for that matter any other special pedestrian popu- and used hand signals to indicate when they detected vehicles lations, including children, wheelchair users, and the elderly. stopping or departing after a stop. Compared to the control The research team identified 28 candidate treatments from condition, the sound-strips treatment increased the probabil- various literature sources that showed initial potential to ity of detecting stopped vehicles and decreased by more than improve (blind) pedestrian accessibility by improving gap a second the amount of time needed to make a detection; and yield utilization, minimizing risk, and reducing delay dur- however, the treatment did not reduce the number of false ing the crossing task. In this research, treatments are grouped detections. The authors noted that false detections could into six basic categories: result in the pedestrian crossing when moving vehicles are approaching the crosswalk. The second study was an experi- 1. Driver information treatments, ment conducted at a double-lane roundabout. In that envi- 2. Traffic calming treatments, ronment the rumble-strip-like treatment was not effective in 3. Pedestrian information treatments, increasing detection of yielded vehicles. The authors attributed 4. Crosswalk geometry modification, this to the fact that the majority of vehicles stopped before 5. Signalization treatments with APS, and crossing over the rumble strips. A "Yield to Pedestrians State 6. Grade-separated crossings. Law" sign that was placed in between the two travel lanes resulted in an increase in drivers' yielding from 11% of vehi- Each category is intended to categorize treatments based cles in the control condition to 16% in the experimental con- on their principal intended effect on vehicle operations. They dition. It was concluded that the treatments explored in these are discussed in more detail below, and Appendix B provides studies do not appear promising for double-lane roundabouts more detail as well as photographs of most of these treatments. but should be explored further to see if they might work at single-lane crossings. Driver Information Treatments There is evidence (Fitzpatrick et al. 2006) that the use of The Long List of Pedestrian static pedestrian crossing signs that are uncorrelated with Crossing Treatments actual pedestrian presence is unlikely to generate predictably Many different types of pedestrian treatments are available high levels of driver yielding. This is not to say that all signing to aid engineers in designing safe crosswalks. Although there is is ineffective or that signing is not required. However, several limited guidance for choosing when a certain treatment should improvements over static roadside warning signs are possible be implemented, there are resources that can assist in making and are summarized below. good judgments. For instance, the Pedestrian Safety Guide and Countermeasure Selection System (Zegeer et al. 2002) is Continuous flasher: A continuous flashing beacon can an Internet site dedicated to providing practitioners with up- be added to any static sign to make it more visible. The to-date information on engineering, education, and enforce- continuous flasher is a static device in that it will continue ment to improve pedestrian safety and mobility. Another to flash whether a pedestrian is actually at the crosswalk or important source of information is TCRP Report 112/NCHRP not. This type of treatment can become ineffective, espe- Report 562: Improving Pedestrian Safety at Unsignalized Cross- cially if the available pedestrian traffic is not sufficient to ings (Fitzpatrick et al. 2006). This resource contains a detailed provide feedback to the traveling public that the crosswalk overview of pedestrian crossing treatments at unsignalized is actually used on a frequent basis. intersections and midblock locations and presents field study In-roadway warning sign: In-street "Yield to Pedestrians" results on their effects on driver yielding behavior. signs are placed in the roadway between travel lanes to The treatment selection process for NCHRP Project 3-78A increase the visibility of the crosswalk. The signs typically started with a long list of treatments that were believed to post messages such as "State Law Yield to Pedestrians."