Appendix B

Flowchart of Generic Functional Equivalence Process

EXPLANATION OF FLOWCHART

ULTIMATE GOAL

• The ultimate goal in comparing standards addressing a particular problem is assessing the real world performance of the covered vehicles or equipment in reducing fatalities and injuries. The most reliable basis for making that assessment is fatality and injury data directly drawn from actual crashes. Accordingly, the countries involved in making functional equivalence determinations should make appropriate efforts to assure the availability of such data.

GUIDING PRINCIPLES

• Best available evidence
  • Country A should base its FE determinations on the best available evidence. If available, estimates of real world safety benefits based on fatality and injury data directly drawn from actual crashes are the best evidence. If such data are not available, then estimates based on other information, such as compliance test data, may be used, although increased caution needs to be exercised in making judgments based on those estimates. If sufficient crash data regarding real world safety benefits are available, and a comparison of those benefits shows that the Country B standard is less beneficial than the Country A standard, Country A could avoid wasting resources making comparisons on the basis of less definitive types of evidence.

  Sufficiency of evidence

  • Many types of data are available for a comparison of two standards. Often there is an abundance of one type of data and little or no data from other sources. If insufficient data are available, and such data either cannot be generated through engineering analysis (e.g., real world safety benefits estimates), or conducting additional research and development is not cost effective, then Country A should immediately stop consideration of such data and consider the other available data instead.

    The horizontal path through the flowchart is intended to illustrate the sources of data that will be considered and a rough idea of the priority they will receive. Each step branches independently to the tentative determination of functional equivalency by its "yes" path. This may seem to preclude later steps once any "yes" path is encountered. In practice, however, all data sources will be considered to the extent that they are available before a determination of functional equivalency is made.

  Best practices

  • Country A should pursue a "best practices" policy, i.e., Country A should propose to upgrade its standards when it concludes that a Country B standard offers greater benefits than its counterpart Country A standard.

  Conservatism

  • Country A should place priority on preserving the safety benefits of its standards. Country A can best preserve those benefits by being conservative in reaching any conclusion that Country B standard is FE to its counterpart Country A standard.

  Reciprocity

  • Country A should take steps to encourage reciprocity by Country B. When Country A's comparison of standards indicates that one of its standards has benefits equal to or greater than its counterpart Country B standard, Country A should forward the results of that comparison to Country B and request consideration be given by Country B to determining that the Country A standard is FE to its counterpart Country B standard.

NOTES

1.  
2. Instead of issuing a proposal to amend its standard by adding the alternative of complying with Country B's standard, Country A may decide to propose seeking to harmonize its standard with the foreign standard. This approach would enable Country A to maintain a single set of requirements and test procedures in its standard, thereby minimizing any effect on its enforcement resources.
3. There may be circumstantial differences, such as special environmental conditions, driver demographics, driver behavior, occupant behavior (e.g., level of safety belt use), road conditions, size distribution of vehicle fleet (e.g., proportion of big versus small vehicles and disparity between extremes), that could influence real world safety benefits. These differences may result in a particular standard having a safety record in one political jurisdiction that does not translate to the other jurisdiction.
4. Differences from model to model and manufacturer to manufacturer in margins of compliance may confound efforts to assess the relative stringency of two standards.