How do you calculate the Crash Indicator BASIC Measure?
The Crash Indicator BASIC (Behavior Analysis and Safety Improvement Category) Measure is calculated as the sum of the severity and time weighted applicable crashes divided by the average number of PUs times the Utilization Factor.
Crash Indicator Measure = Total of time and severity weighted applicable crashes ÷ Average PUs x Utilization Factor
In order to fully understand the formula, the individual components must be defined and explained.
Severity weight
More emphasis is placed on crashes with more severe consequences. For example, a crash involving an injury or fatality is weighted more heavily than a crash where only a tow-away occurred. A hazmat release also increases the weighting of a crash. The table below illustrates this:
| Crash Type | Crash Severity Weight |
| Involves tow-away but no injury or fatality | 1 |
| Involves injury or fatality | 2 |
| Involves a hazmat release | Crash Severity Weight (from above) + 1 |
Time weight
All crashes are assigned a time weight of 1, 2, or 3. The time weight of an event decreases with time, resulting in more recent events having a greater impact on an entity’s BASIC Score than events from the more distant past.
Accidents recorded:
- In the past 6 months are time-weighted at 3;
- Over six months and up to 12 months are time-weight at 2; and
- More than 12 months ago but within 24 months are time-weighted at 1.
Events older than 24 months are assumed irrelevant and no longer used.
Normalization using PUs/VMT
Carriers are normalized using a Utilization Factor that uses the average Power Units (PUs) and Vehicle Miles Traveled (VMT) based on the Motor Carrier’s Census Data.
Average PUs is used to account for each carrier’s level of exposure. The number of commercial motor vehicles includes the number of owned, term-leased, and trip-leased power units (trucks, tractors, hazardous-material tank trucks, motor coaches, and school buses) contained in the Census Data.
The primary sources of power unit information in the Census are Forms MCS-150 and MCS-151. Carriers are required to update their MCS-150 information biennially. The average PUs for each carrier is calculated using:
- The carrier’s current number of PUs,
- The number of PUs the carrier had in the middle of the first time period (i.e., 18 months ago), and
- The number of PUs the carrier had in the middle of the second time period (i.e., 6 months ago).
Average PU = PU current + PU 6 months ago + PU 18 months ago ÷ 3
The Utilization Factor is calculated in three steps:
- Find out your carrier’s segment based on your MCS-150 and enforcement's MCS-151 (completed as a part of an investigation).
- Combo. This includes combination trucks and/or motorcoaches constituting 70 percent or more of your power units, or
- Straight. Straight trucks or other vehicles constituting more than 30 percent of your power units.
- Calculate VMT per average PU. Look at your VMT based on your MCS-150 Census Data. Divide VMT data by average PUs.
- Using the information in steps 1 and 2, use the following tables to calculate your utilization factor.
| VMT per Average PU | Utilization Factor |
| <80,000 | 1 |
| 80,000 – 160,000 | 1+0.6[(VMT per PU-80,000)/80,000] |
| 160,000-200,000 | 1.6 |
| >200,000 | 1 |
| No recent VTM information | 1 |
| VMT per Average PU | Utilization Factor |
| <20,000 | 1 |
| 20,000-60,000 | VMT per PU/20,000 |
| 60,000-200,000 | 3 |
| >200,000 | 1 |
| No recent VMT information | 1 |