Two pockets: layover fee the carrier bills the shipper for overnights, and the driver's IRS per-diem (full days at 100%, partial travel days at 75%).
Multiplier applies to layover only (weekend / holiday premium). Per-diem is unaffected.
Day equivalents: 2.50 (full days + partial × 0.75)
Source: IRS Revenue Procedure — transportation-industry M&IE per-diem ($80/day CONUS, $86 OCONUS for fiscal 2026, adjusted annually). Partial-day 75% per IRS Publication 463. Layover fee amount is per carrier tariff — no standard federal rate.