Occupational (OSHA) and Environmental Hazards/safe man hours for driver


Dear Mr.Brown,

Is there any formula for calculating safe man hours for drivers. If so please guide me how to calculate.

Subject: safe man hours for driver

Question: Dear Mr. Brown - is there any formula for calculating safe man hours for drivers. If so please guide me how to calculate.

Answer: Most companies and organizations I am aware of use the same method of calculating the safe man hours for drivers as are used for the number of safe man hours for all employees. In the U.S. under OSHA most use the calculation for INCIDENT RATE which is calculated by:

INCIDENT RATE = (the number of incidents [to the drivers] x 200,000 [an OSHA constant]) divided by the total number of driver hours worked

Note: The hours worked by the drivers include all hours on the job including behind-the-wheel hours. Loading, unloading and time spent waiting for loads would be included.

Example: 300 drivers work for the period of time being used (week, month, year, etc) with 5 incidents in the period of one year or 675,000 hours (45 hours per week x 50 week x 300 drivers). Thus the INCIDENT RATE = (5 x 200,000)/675,000 = 1.48

Many places in the world use the term FREQUENCY RATE instead of INCIDENT RATE. The calculation is as follows:

FREQUENCY RATE = (the number of accidents [driver injuries] x 1,000,000 [a constant developed by the old National Safety Council] divided by the total number of driver hours worked.

Example: with the same figures as used in the example for INCIDENT RATE the calculation would be as follows: FREQUENCY RATE = (5 X 1,000,000)/675,000 = 7.41

It would take many pages to explain the differences between the two and how they came to be and in the end much of it makes little or no sense but then that would be expected since as you might suspect the bureaucracy became involved. I hope this provides you with the information you need. If I can be of further assistance please feel free to ask.

Michael Brown, CSP Retired

Occupational (OSHA) and Environmental Hazards

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Mike Brown CSP Retired


I specialize in the professional management of occupational safety and health as well as workers` compensation to reduce losses and improve production and address related issues through a comprehensive approach by senior management using proven principals.I worked for over twenty (20) years in the management of occupational safety, health and workers` compensation and safety training (Retired from employment in 1996 due to a stroke, which prevented the extensive travel required).

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