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27 to generate the FHWA BCI (see Harkey). They employed a The proposed CRC index includes the following variables: web-based survey consisting of questions and thirty-two 30-second video clips. Quality of Paved Shoulder; The 30-second video clips were edited from 15-minute Size of Cycling Space; videos shot with image stabilization from a car moving 10 mph Auto Speed; at a height 4.5 feet above the ground. Given that overtaking Auto Flow; motor vehicle traffic tended to give wide clearance to the slow Truck Flow; moving car on the shoulder, the video clips tended to show Roadside Conditions (e.g., sand, gravel, and vegetation); over-taking vehicles giving bicyclists more clearance than Roadside Development; they would in reality. The clips were digitized in Windows Vertical Profile; Media Player compressed format for easy downloading by Longitudinal Visibility; and survey participants. Major Intersections. Participants for the web-based survey were recruited through letters to various bicycle groups, flyers distributed at 3.4 Pedestrian Perceptions of LOS popular recreational bicycling facilities, and personal recruit- ing by the authors. Researchers have used field intercept surveys and closed A total of 101 participants (of which 56 were classified as ex- course surveys in the field to measure pedestrian perceptions perienced) successfully completed the survey. The experience of level of service. Some distributed questionnaires in the field level of the respondents was determined by induction from the to be returned later via the mail. responses to a few key questions. Slightly fewer than 20% of the Various definitions of level of service have been developed respondents were female. None were under 18 years of age. (e.g., LOS A is defined as "best," "most safe," "very satisfied," Three linear regression models (one for experienced riders, or "excellent" depending on the researcher). one for casual riders, and one for all riders) were fitted to the Some researchers have asked pedestrians to directly rate mean responses for each video clip. The best model included the level of service of a sidewalk or intersection, while others all bicyclists. The compatibility index in this model was a have sought to derive the LOS rating indirectly from the function of only two factors: shoulder width, and the volume pedestrian's choice of which sidewalk and crosswalk to use. of heavy vehicles traveling in the same direction as the bicy- Several researchers have focused on the intersection cross- clist. The model had an R-square value of 0.67. ing environment. Most have looked at the sidewalk environ- Jones and Carlson intentionally excluded pavement con- ment. A few have looked at mid-block crossings in between dition from the survey because of various data difficulties (in- intersections. cluding the difficulty of representing rough pavement in a None of the researchers have incorporated Americans with video shot from a camera mounted on a car). All sites had rel- Disabilities Act (ADA) considerations in their measurement atively level grades, only two traffic lanes, and speed limits in or prediction of pedestrian LOS. None of the research is excess of 50 mph. specifically applicable to individuals with disabilities. Noel, Leclerc, and Lee-Goslin [43] recruited bicyclists al- ready using various rural routes to participate in a survey of Intersection Crossing LOS Studies bicycle compatibility. A total of 200 participants were re- cruited at 24 sites. Bicyclists were stopped at the start of each Several studies focused on specific pedestrian facility types test segment and asked to participate in the study. Those con- to identify the key variables that determine level of service senting were then interviewed to determine their characteris- there. Some focused on methods of determining LOS for tics (e.g., age and city of residence). Participants were given pedestrians at crossing locations. segment and junction rating cards to evaluate six sites on each Hubbard, Awwad, and Bullock [44] developed a signal- segment. The cards were collected at the end of the segment ized intersection model for pedestrian LOS based on the and the participants were then asked about various potential percentage of pedestrian crossings affected by turning factors affecting safety at the junctions. vehicles. The respondents were grouped into three experiential Chilukuri and Virkler [45] sought refinements to the HCM types: sport cyclists, moderate cyclists, and leisure cyclists. 2000 equation for pedestrian delay at signalized intersections, The survey found the following key factors affecting per- which assumes pedestrians arrive at an intersection randomly. ceived comfort and safety (ranked by order of importance): They performed a study of coordinated signal intersections riding space available to cyclist, traffic speed, presence of and found that pedestrian delays were significantly different at heavy vehicles, pavement conditions, presence of junctions, these locations than expected if arrivals were random. The and finally, vertical profile of the route. authors concluded that the HCM pedestrian delay equation