The problem: Accidents, deaths, and injuries are "lagging" indicators, in the sense that they tell us after things have already gone wrong. "Leading" indicators, on the other hand, might be useful in warning us about changes in risk before the system has failed. For example, changes in demographics present a leading indicator for driver safety. We might also consider looking at certain industry safety practices, vehicle age, operator attitudes, training programs, or any number of variables that could be used as leading indicators for safety, if significant correlations can be found.
There has been a strong focus in DOT on safety outcomes, but often only subjective assessments of the relationship between contributing factors and the resulting accidents, deaths, and injuries. This limits our ability to intervene early in the process, and may result in program designs that are not as targeted or as cost-effective as they could be.
What we need: We need indicators which signal future changes in safety, and that are based on demonstrated correlations. To develop such indicators, we need to first tap the expert knowledge in the various modes to help identify factors that are suspected to be leading indicators. Then we need to develop hypotheses and design research projects to test the hypotheses. This may be a continuous process, not a one-time project. Finally, we need to look at the data collection process itself, and the experience of the data collectors, to determine how best to improve the data.
Benefits: Leading indicators could help us forecast trends, and we could use that information to help set more realistic (or ambitious) program goals. The results of the research to identify leading indicators could also be used to target or redirect programs for greater effectivenessfewer fatalities and injuries.