William W. Hunter

Motor vehicle and roadway factors in pedestrian and bicyclist injuries: an examination based on emergency department data

Information on 2558 persons treated for injuries incurred while bicycling or walking was collected from eight hospital emergency departments over approximately a one-year time period. The emergency departments represented a mix of urban and suburban/rural sites in three states--California, New York, and North Carolina. The data were collected on special survey forms and included detailed information about the location of the injury event. Results show that, overall, 70% of the reported bicycle injury events and 64% of the reported pedestrian injury events did not involve a motor vehicle. In addition, 31% of the bicyclists and 53% of the pedestrians were injured in non-roadway locations such as sidewalks, parking lots, or off-road trails. Although pedestrians and bicyclists struck by motor vehicles in the roadway were generally the most seriously injured, they represented less than a third of the reported cases. Increased knowledge of non-roadway and non-motor vehicle pedestrian and bicyclist injury events can contribute to more effective program and countermeasure development to improve pedestrian and bicyclist safety.

Evaluation of Blue Bike-Lane Treatment in Portland, Oregon

Many European cities use colored markings at bicycle–motor vehicle crossings to reduce conflicts. To determine whether such colored markings help improve safety at American bicycle–motor vehicle crossings, the city of Portland, Oregon, studied the use of blue pavement markings and a novel signage system to delineate selected conflict areas. The University of North Carolina Highway Safety Research Center (HSRC), under contract to FHWA, analyzed the project data. From 1997 to 1999, Portland marked 10 conflict areas with paint, blue thermoplastic, and an accompanying “Yield to Cyclist” sign. All of the sites had a high level of cyclist and motorist interaction, as well as a history of complaints. The crossings were all at locations where the cyclist travels straight and the motorist crosses the bicycle lane in order to exit a roadway (such as an off-ramp situation), enter a right-turn lane, or merge onto a street from a ramp. The study used videotape analysis and found most behavior changes to be positive. Significantly higher numbers of motorists yielded to cyclists and slowed or stopped before entering the blue pavement areas, and more cyclists followed the colored bike-lane path. However, the blue pavement also resulted in fewer cyclists turning their heads to scan for traffic or using hand signals, perhaps signifying an increased comfort level. The overwhelming majority of cyclists and close to a majority of motorists surveyed felt the blue areas enhanced safety. Colored pavement and signage should continue to be used and evaluated in bicycle–motor vehicle conflict areas.

Observed and self-reported seat belt wearing as related to prior traffic accidents and convictions.

During the summer of 1987, 10,000 color-coded mailback questionnaires that identified belted and unbelted North Carolina drivers were handed out at the 72 sites that constitute the probability sample for determining the statewide belt use rate in North Carolina. By obtaining identifying information to determine the winner of a

Pedestrian Crash Types: 1990s Update

500 prize from among the 5,074 respondents, police-reported traffic accident and conviction records from the North Carolina driver history file were linked to the belted and unbelted respondents. Analyses found that drivers who had been observed not wearing seat belts had 35% more accidents and 69% more convictions than did belted drivers in the previous four-year period. Similar findings were obtained from self-reported belt use.

Bicyclist Intersection Safety Index

A report is given on an application of the NHTSA pedestrian crashtyping system for categorizing pedestrian-motor-vehicle crashes according to the specific sequence of events leading up to individual crashes. Results are based on a recent sample of over 5,000 pedestrian crashes drawn from six states and reported by police. Over 80 percent of the pedestrian crashes fell into the following crash type categories: vehicle turn or merge (9.8 percent), intersection dash (7.2 percent), driver violation at intersection (5.1 percent), other intersection (10.1 percent), midblock dart or dash (13.3 percent), other midblock (13.1 percent), not in roadway and waiting to cross (8.6 percent), walking along roadway (7.9 percent), and backing vehicle (6.9 percent). These crash types were found to vary according to the characteristics of the pedestrian and factors of the location, environment, and roadway. The process of typing pedestrian crashes can be a valuable tool at both the state and local level for developing more h...

THREE-STRAND CABLE MEDIAN BARRIER IN NORTH CAROLINA: IN-SERVICE EVALUATION

Each year many bicyclists are injured or killed in intersection-related crashes with motor vehicles. The objective of this study was to develop a macrolevel bicycle intersection safety index (Bike ISI) that would allow engineers, planners, and other practitioners to use known intersection characteristics to prioritize intersection approaches with respect to bicycle safety proactively. Using variables that indicate a higher probability of risk for bicyclists, the Bike ISI identifies which intersection approaches have the highest priority for bicycle safety improvements within a particular jurisdiction. Using video data and online ratings surveys, this study obtained data on avoidance maneuvers and safety ratings at 67 intersection approaches and developed a Bike ISI model that incorporated both measures of safety. The Bike ISI uses data on the traffic volume, the number of lanes, the speed limit, the presence of a bike lane, the presence of parking, and the presence of traffic control to give a rating for an intersection approach according to a six-point scale. Using the Bike ISI, practitioners have the ability to evaluate each approach at all intersections in their jurisdictions or at a select group of intersections. Once safety index values are assigned to each site, the practitioner can then select the sites with the highest index values and conduct more detailed reviews of those sites to determine whether any treatments are needed to improve the safety of the intersection.

Evaluation of Innovative Bike-Box Application in Eugene, Oregon

By using historical crash data, several regression-type models were developed with which to estimate the effects of the installation of cable median barrier on crash rates for several crash types while taking into account several other factors associated with variation in crash occurrences or crash rates. The data for these analyses consisted of counts of crashes of the various types for each section of North Carolina Interstate highway, along with the associated roadway characteristics, for 1990 through 1997. Certain roadway characteristics (in particular, traffic volume) changed from year to year as, of course, did the crash counts. The entire North Carolina Interstate system was taken as a reference population; a negative binomial error structure was assumed for many of the models, and the models contained specific effects for each crash year to account for various unmeasured effects that may vary from year to year (e.g., weather conditions). These models used the reference population to predict numbers of crashes on the cable sections. After cable barrier installation, none of these crashes occurred. In summary, these analyses indicate that several types of crashes (e.g., ran-off-road-left, hit-fixed-object) increased on the sections where cable median barrier was installed. However, these sections showed improved overall safety through fewer serious and fatal crashes as well as fewer head-on crashes. Overall severity index values were greatly reduced after cable barrier installation.

Police Reporting of Pedestrians and Bicyclists Treated in Hospital Emergency Rooms

An innovative “bike box”—a right-angle extension to a bike lane (BL) at the head of the intersection—was installed with accompanying traffic signs but no extra traffic signals at a busy downtown intersection featuring two one-way streets in Eugene, Oregon, in summer 1998. The box allows bicyclists traveling to the intersection in a left side BL to get to the head of the traffic queue on a red traffic signal indication and then proceed ahead of motor vehicle traffic toward a right side BL when the traffic signal changes to green. Cyclists traveling through the intersection were videotaped before and after placement of the box. The videotapes were coded to evaluate operational behaviors and conflicts with motorists, other bicyclists, and pedestrians. Twenty-two percent of the bicyclists who approached in the left side BL and then crossed to the BL on the right side of the street (the bicyclists for whom the box was most intended) used the box. Many more bicyclists in this target group could have used the box (i.e., they had a red signal indication and enough time to move into the box). A problem with motor vehicle encroachments into the box likely diminished the frequency of use. The rate of conflicts between bicycles and motor vehicles changed little in the before and after periods. No conflicts took place while the bike box was being used as intended.

Diagnosis of Schizophrenia: Pathognomonic Signs or Symptom Clusters

Drawing on a study of injured pedestrians and bicyclists treated at hospital emergency rooms in California, New York, and North Carolina, an attempt was made to match the emergency room cases to state motor vehicle crash data, and to analyze the factors associated with the occurrence of a match. The purpose is to (1) provide additional information on the likely level of underreporting of pedestrian– and bicycle–motor vehicle collisions on state crash files and (2) examine whether cases that are reported differ in any systematic way from those that are not reported. A total of 388 pedestrian– and 255 bicycle–motor vehicle cases were available for inclusion in the analysis, with 56 percent of the pedestrian and 48 percent of the bicycle cases matched to state crash files. After adjusting for other potential confounders, pedestrians who were hospitalized or killed were 1.3 times more likely to be reported on the state crash files than were pedestrians receiving emergency room treatment only; those struck in the roadway were 1.7 times more likely to be reported than those struck in nonroadway locations; and those ages 15 to 24 were 70 percent less likely to be reported than pedestrians of all other ages. In contrast, the only factor found to be associated with police reporting of bicycle–motor vehicle crashes was the severity level of the injury: bicyclists who were hospitalized or killed were 1.4 times more likely to be reported on the state crash files than were bicyclists receiving emergency room treatment only.

Conversions of wide curb lanes : The effect on bicycle and motor vehicle interactions

LTHOUGH A it has long been a focus for professional concern, psychiatric diagnosis remains the greatest impediment to investigative work in schizophrenia. Feighner et al.’ l discussed the difficulties involved in arriving at a research definition of schizophrenia, while the unreliability of the psychiatric diagnosis of schizophrenics has been documented thoroughly.8*‘7 DS M-II,2 revised to alleviate some of the vagueness and ambiguity of DSM-I,’ has led to even more controversy regarding objective criteria for the diagnosis of schizophrenia.32 The inadequacies of DSM-II, especially with regard to its lack of specificity in the definition of terms used to define schizophrenia and its inadequacy as a nomenclature, have been discussed extensively.1s.17 Many investigators beginning with Kraepelin”’ have attempted to establish pathognomonic criteria that brought together patients with varied phenomenology under the same diagnostic class. For example, Bleuler5 described four general primary symptoms of schizophrenia which included loose associations, flat affect, autism and ambivalence as well as secondary symptoms called ego functions. However, this system has been considered inadequate since it uses imprecise terminology, mixes theoretical concepts with observations and because such symptoms also are prevalent to some degree in other physical and psychiatric disorders.32 While initially considered to have some basic validity and explanatory power, Bleuler’s concepts now receive little support.12 The most impressive effort to date in describing pathognomonic symptoms of schizophrenia has been described by Schneider. 27 This phenomenologic system includes 11 first rank order symptoms (FRS) which include three forms of auditory hallucinations, delusions, somatic passivity, thought insertion, thought withdrawal, thought broadcasting, and affect impulses or motor activity experienced as imposed and controlled from the outside. A detailed explanation of each symptom can be found elsewhere. g These FRSs are regarded as pathognomonic of schizophrenia when one is present in the absence of somatic illness. While the FRSs were chosen pragmatically according to their ease of identification, with no relation to theory, no empirical tests of the predictive validity of these concepts were conducted until recently. Mellor2’ found that 72% of 166 newly admitted schizophrenics demonstrated