41 CFR 302-4.400: -4.400 Minimum daily driving distance.

Agencies may establish a reasonable minimum driving distance that may be more than, but not less than an average of 300 miles per calendar day. Exceptions to the daily minimum driving distance may be granted by the agency when there is a delay beyond an employee's control such as acts of God, restrictions by governmental authorities, or other acceptable reasons (e.g., the employee is an individual with a disability as defined by Section 501 of the Rehabilitation Act of 1973 and its implementing regulations at 29 CFR 1614.203 or has special needs).