• Following the BASIC (Behavior Analysis and Safety Improvement Category) Measure calculation, data sufficiency standards are applied to ensure there is enough data.
• After the data sufficiency steps are completed and carriers are compared against their peers, a percentile ranking is assigned.
• The percentile ranking in comparison to the carrier's peers is the Compliance, Safety, Accountability (CSA) Driver Fitness BASIC Score used to determine whether an intervention is necessary.

Once the Driver Fitness BASIC Measure is calculated, the Safety Measurement System (SMS) employs data sufficiency standards to ensure that there are enough inspections to produce meaningful measures of safety for carriers. In instances where the safety performance of a carrier can potentially lead to CSA interventions or a detrimental Safety Fitness Determination, additional data sufficiency tests are employed. These tests ensure that a carrier has a “critical mass” of poor performance data or a pattern of violations before adverse action is taken.

Step 1

For the Driver Fitness BASIC, the first step in data sufficiency requires the Federal Motor Carrier Safety Administration (FMCSA) to remove carriers with:

• Less than five relevant driver inspections, or
• No inspections resulting in at least one violation in that BASIC.

Step 2

Motor carriers are ranked in safety event groups. Grouping motor carriers in safety event groups (i.e., peers) allows the SMS to handle the widely diverse motor carrier population, while ensuring that similarly situated carriers are treated with the same standards.

The following table lists the groups for the Driver Fitness BASIC:

Safety Event Group Category	Number of Relevant Inspections
1	5-10
2	11-20
3	21-100
4	101-500
5	501+

Within each group above, the SMS ranks all the carriers’ BASIC Measures in ascending order. Percentile ranking allows the safety behavior of an entity to be compared with the safety behavior of its peers. Within each peer group, a percentile is computed on a 0-100 scale for each entity that receives a non-zero measure, with 100 indicating the worst performance.

Step 3

Yet another data sufficiency is employed. Carriers that meet both of the following criteria are eliminated:

• No recorded violations in the past 12 months, and
• No violation in the BASIC recorded during the latest relevant inspection.

Step 4

Those carriers that remain after the second data sufficiency step have been assigned a BASIC Score. Carriers with percentiles above a certain set threshold will be identified for potential CSA interventions.