OOSC, Part II, Item 1. Brake System - 20% Brake Chart

The note ** in the OOSC under the chart in Part II, Item 1. Brake System a. Defective Brakes for 20% brake defects is confusing when determining how many defective brakes are required to place a combination OOS. The way it is worded leads you to believe that if you have a vehicle with 24 brakes that you would do the 20% which would result in 4.8 defects but the next sentence indicates that you would round down to the next whole number when in actuality you round up to the next whole number as all the combinations in the chart above reflect.

When the brake chart is referenced in the OOS criteria for vehicle combinations of axle configurations greater than outlined in the chart, the note could result in an error in calculations for OOS. An amendment should be made for the note in the OOS criteria to clearly outline the rounding up or down of decimal points when determining number of defective brakes required vs number of brake defects present.

The following is a suggested amendment to the wording for the chart outlined in Section 1a Defective Brakes to clarify the number of defective brakes needed vs the number of defective brakes present. ** For a vehicle or combination that exceeds 22 brakes. Determining 20% Defective Brakes: Determine the number of defective brakes required by using 20% of the total number of brakes on the vehicle or combination (i.e. 24 x .20 = 4.8%). Round all fractions up to the next whole number (i.e. 4.8% = 5 required defective brakes). Calculating Brake Violations to Defective Brakes: When determining the number of defective brakes, round all fractions down to the next whole number (i.e. 4.5 brake violations = 4 defective brakes).