Travel on official time
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
Insofar as practicable travel during nonduty hours shall not be required of an employee. When it is essential that this be required and the employee may not be paid overtime under § 550.112(e) of this chapter the official concerned shall record his reasons for ordering travel at those hours and shall, upon request, furnish a copy of his statement to the employee concerned.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.