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FHWA Home / Policy & Governmental Affairs / Conditions and Performance Report

Conditions and Performance Report

Conditions and Performance Report
Chapter 11—Afterword - A View to the Future

Conditions and Performance Chapter Listing

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Introduction


 

Safety

As the foremost goal, safety is clearly of great importance to the Department of Transportation, as it is to all of us. Safety is the first goal listed in the FHWA strategic plan, and with good reason. Fatalities and injuries on the nation's highways are not something for which we as a nation can be complacent. We are always striving to reduce injuries, including fatalities, the most serious form of injury. Safety initiatives have been developed on a number of fronts. Safer highways, safer vehicles, and safer drivers are all important achievements and all have contributed to greater safety on the highways than in the past. Fatality rates have been reduced significantly even while highway travel has increased dramatically. For example, from 1966 to 1997 the fatality rate per 100 million vehicles miles of travel has declined from 5.5 to 1.6. This occurred while travel increased from 926 billion to 2,576 billion vehicle miles.

Indicators of the safety aspects of performance are relatively easy to identify but difficult to isolate because of the many different influences on the causation. Safer vehicles (transit cars, buses, trucks, autos) are one aspect. Safer infrastructure contributes a more forgiving environment. Safer operation of the vehicles by professionals and amateurs alike yield the benefits of fewer crashes. The net effects of all of these facets are reflected in fatalities and injuries both in total numbers and rates of occurrence.

What metrics serve to help us evaluate that net result? What method of forecasting can enlighten us as to the potential safety impacts of various future situations? Since safety is imbedded in project design and program operation aspects of all transportation agencies, it is reflected in the Highway Economic Requirements System (HERS) mechanism used to evaluate various alternative investment scenarios. HERS incorporates a crash model that predicts future numbers of crashes based on the information available in the Highway Performance Monitoring System (HPMS) database and on projected highway capital improvements. This crash model has been recently upgraded to be more sensitive to changes in geometrics, such as lane width, shoulder width, and horizontal and vertical alignment. Crash costs, including the costs of injuries and fatalities, are included in the user costs estimated by HERS and are used to evaluate potential highway improvement actions.

These crash costs are evaluated along with other user costs such as the time costs of delay and vehicle operating costs. Therefore the dollar benefits of reduced crashes are included in the benefit/cost analysis by HERS when analyzing the relative benefits of alternative highway improvements. High-way improvements that would be expected to reduce the number of crashes will reduce the costs of crashes, and this reduction is part of the benefits of the improvement. If benefits exceed costs over the life of the improvement, the action is deemed beneficial.

The HPMS database on which the analysis is based includes data on roadway geometrics, travel volumes, vehicle speeds, etc., but it does not include data on the number of accidents that occur on the sample highway sections. Such data were included for several years in the 1980s, but the data were too sparse to be statistically significant. Currently the HPMS contains no data on specific roadway locations regarding number of accidents. Therefore the HERS analysis has no way to address specific high accident locations.

The question asked here is whether the current form of analysis is sufficient to address safety concerns at the national level. HERS can be adjusted to assign a higher value to crash costs than to other user costs. Crash costs could, for example, be doubled with respect to other user costs. This would give crash costs more weight in the benefit/cost analysis than other costs. But such a procedure, it can be argued, would invalidate the premise of basing the analysis results on values that are assigned as fairly as possible for all costs. If different weights are arbitrarily assigned to different components of user costs, that could be construed as predetermining the results of the analysis. If we wish to claim that a dollar in crash costs is worth more than a dollar of delay, sensitivity analysis can be done to determine how much change in investment strategy would result.

How can transit safety be related to the overall analysis? The safety of bus transit may be related to overall highway safety, but to what degree? The safety of rail transit, whether light or heavy rail, would typically be a separate issue from highway safety.

There is no intent implied here for FHWA to develop a specific program of highway safety projects for the States. Instead the concern is whether safety is adequately addressed in the national level analysis for this report. In other words, does the analysis that we perform for this report adequately address concerns about highway crashes? If more attention were paid to highway improvements that enhance safety more than capacity or pavement condition, what would the scenario look like? Would it be very different from what HERS now recommends? Should more attention be paid to facilities that are substandard from a safety standpoint-width, alignment, shoulders, etc?

The national investment analysis that we now perform is not intended to dictate what highway improvements the States will accomplish. The analyses are rather intended to demonstrate what can be accomplished with given investment levels, with user costs and agency costs being minimized for each scenario. Safety is one of the major inputs to each scenario, and this may be the way to continue.

 

 
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Page last modified on November 7, 2014
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000