41 CFR § 301-10.309
What will I be reimbursed if I am authorized to use common carrier transportation or a rental vehicle and I use a POV instead?
June 9, 2020
You will be reimbursed the applicable POV rate on a mileage basis, plus per diem, not to exceed the total constructive cost of the authorized method of common carrier transportation plus per diem. Your agency must determine the constructive cost of transportation and per diem by common carrier under the rules in §301-10.310.
[FTR Amdt. 2015-03, 80 FR 27260, May 13, 2015]