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How is the "Top 30%" OOS, Hazmat violations, and crash ratings calculated?

The "top 30%" is a factor defined by examining ALL motor carriers registered for a USDOT Number. The factor establishes a threshold where in the total population of motor carriers, 30% of them fall above the number for out-of-service rates and crashes at the 70th percentile. The "top 30%" threshold rates will remain static rather than change every two years and are published on the FMCSA website, for motor carriers to determine their ability to transport permitted Hazardous Materials.

Since the inception of the program, data from the entire eight year period was used in the calculations for the new fixed rates. The threshold rate calculation included only carriers that had at least 12 inspections over the 8 years. The top (worst-performing) 30% of the National averages were determined by establishing a cut-off at the numerical threshold value located at the 70th percentile in each category using eight years of data. All carriers with a driver, vehicle, or HM OOS rate less than the cut-off are considered to be below the National Average for each category, and, therefore, eligible for participation in the program. Carriers with a driver, vehicle, or HM OOS rate that is equal to or greater than the cutoff in each category are in the 30%, or the worst-performing category, and will be denied an HMSP.

Motor carriers that transport permitted HM may obtain their out-of-service rates from their Company Safety Profile  and compare it to the national rates posted on the FMCSA website.

In order to calculate the fixed crash rate the 8-year period, since the inception of the program, was divided into four 2-year periods. Qualifying motor carriers had at least 2 crashes in at least one 2-year period. Then the number of power units for each qualifying 2-year period was captured based on snapshots taken immediately after the end of each FY. The crash rate for each 2-year period motor carrier was then determined in each time period by taking the number of crashes indicated and dividing by the number of power units times two. Finally, all carrier/time period combinations were ranked based on crash rate, with a resulting crash rate threshold at the 70th percentile of 0.136.

A motor carrier may determine its crash rate as the number of crashes divided by the number of power units as follows: HM Permitted Motor Carrier crash rate = Number of crashes in the past 365 days / total number of power units (operating).

The New Fixed Rates are: Driver: 9.68; Vehicle: 33.3; HM: 6.82; Crash: 0.136. These rates are now in effect and are being used to establish a company's eligibility for an HMSP. Detailed information on the method used to calculate these rates is published on FMCSA's SAFER website. The Federal Register notification can be viewed at 77 FR 38215

Last Updated : April 15, 2014
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