What is the allowance called that is paid on a "per mile" basis for authorized travel?

The allowance that is paid on a "per mile" basis for authorized travel is referred to as the Monetary Allowance in Lieu of Transportation (MALT). MALT specifically compensates individuals for the use of their personal vehicles while conducting official business and is calculated based on the distance traveled. This is distinct from other types of travel allowances, which may cover lodging, meals, or other expenses.

Daily Allowance is generally associated with food and accommodation costs, not mileage. Reimbursed Travel Expenses is a broader term that can encompass various forms of compensation but does not specifically address mileage. Travel Per Diem is commonly used to refer to a daily allowance that covers all costs associated with travel, again focusing mainly on meals and lodging rather than mileage specifically. Therefore, MALT is the precise terminology recognized for the per-mile compensation, making it the correct choice in this context.