Appendix D to Part 1240 - Determination of National Average Seat Belt Use Rate
23:1.0.2.14.8.4.1.1.45 : Appendix D
Appendix D to Part 1240 - Determination of National Average Seat
Belt Use Rate
A. To determine the national average seat belt use rate in a
calendar year, each State seat belt use rate for the calendar year
will be weighted to reflect the percentage of total national
vehicle miles traveled attributable to that State.
B. If a State seat belt use rate is unavailable for a State
during a calendar year (either because the State did not conduct a
seat belt use survey or a survey was conducted but does not comply
with the Uniform Criteria for State Observational Surveys of Seat
Belt Use, 23 CFR Part 1340), NHTSA will calculate a State seat belt
use rate, using the last available State seat belt use rate
determined under § 1240.11 or § 1240.12 of this part, as
applicable, along with information on seat belt use rates from the
FARS, and an algorithm relating FARS seat belt use rates to
observed seat belt use rates (see Appendix 1, note). This procedure
will produce an estimated State seat belt use rate for the unknown
calendar year. The estimated State seat belt use rate will then be
weighted in the manner described in paragraph A of this
appendix.
C. The national average seat belt use rate for the calendar year
will be determined by adding the weighted State seat belt use rates
for each of the States (i.e., the national average seat belt
use rate is the weighted average of all the State seat belt use
rates).
D. NHTSA may elect to use a seat belt use survey that does not
comply with the Uniform Criteria for State Observational Surveys of
Seat Belt Use in determining the national average seat belt use
rate (even though the State that submitted the survey is ineligible
to receive an allocation of funds), if in NHTSA's judgment, the
deficiencies in the survey are not so substantial as to render the
survey less accurate than the FARS estimate.