Safetyand particularly transportation safety continue to dominate our focus on theworld stage. We can see this clearly in the number of journals,publications and citations relevant to safety research. If we look at the mostcited papers during the last decade or so, we can see clearly the interest inmany aspects of safety, most importantly human factors issues such as fatigue,cognitive load and distractions; State-of-the-art in analytical accidentanalysis that enable us to provide better description of many safety phenomenaand more accurate estimations and predictions of safety measures; and thepublic health aspects of safety.
Many improvements have been reached inmany countries around the world in the last decade as evidenced in thesubstantial road fatality reduction in many countries in Europe, North America,Australia and Japan. However the challenges in other countries are many,particularly in the fast rising economies of East Asia and the developingcountries in different parts of the world. There are still much needed work tobe done on all fronts by researchers, practitioners and decision makers tobring safety problems under control. Research paves the way for safer roads anda safer future.
Mohamed Abdel-Aty, PhD, PE
An example may be helpful to show how more accurate knowledge of crash factors, including better precrash and noncrash data, can lead to more effective use of crash countermeasures. Run-off-the-road crashes account for 33 percent of highway fatalities (FHWA, personal communication). Potential factors in these crashes include roadway geometry (a curved road, for example); excessive speed for that geometry; absence or inadequate visibility of lane markings or signs indicating the road’s curvature; the presence or absence of a guardrail; the presence or absence of objects (such as signposts, trees, and walls) that may be struck by an errant vehicle; vehicle malfunction, such as brake failure; driver behavior, such as safety belt use and braking; and driver distraction, fatigue, or substance abuse.
To know the importance of road geometry, it is necessary to have accurate data about crash location. Often these data are only approximate (to the nearest mile marker, for instance) or are not available at all (because they were inadvertently omitted from the police report or purposely excluded from the data set to protect privacy). As a result, it is difficult to pinpoint high-accident locations and establish reliable relationships between crash types or severity and particular roadway geometries. The use of GPS can help identify crash locations with much greater accuracy. More accurate crash location data can also allow researchers to see exactly what pavement marking, signage, guardrail, and other traffic control and safety appurtenances and roadside objects are at the scene.
Speed is usually estimated from physical evidence associated with the crash, such as skid marks (if the vehicle does not have antilock brakes) and damage to vehicles and other objects. In some cases, speed can be determined by interviewing witnesses or someone involved in the crash. These methods (especially interviews) are only approximate, however, and can be extremely inaccurate. EDRs can provide accurate speeds, as well as changes in speed (delta V) during the crash. In addition, if EDR and GPS technologies are used to gather information about typical speeds on similar geometries where crashes do not occur, researchers will have a much better idea of how significant a factor speed is in crashes and what ranges of speeds may be safer.
As noted, EDRs can provide highly accurate data on vehicle functions, as well as some aspects of driver performance or behavior. A driver may report that he or she applied the brakes or was wearing a safety belt at the time of a crash. But an EDR will record if and when the brakes were in fact applied and which, if any, of the safety belts in the vehicle were in use.