The main purpose of this legislation is to prevent the federal government from using taxpayer money to support any form of mileage tax. A mileage tax is a fee charged based on the number of miles a vehicle is driven. The bill aims to ensure that no federal funds are allocated for studying, proposing, or enforcing such taxes, including any programs that track vehicle mileage. Key provisions of the legislation include a clear prohibition on the use of federal funds for any activities related to mileage taxes.