The main purpose of this legislation, known as the "Balance the Highway Trust Fund Act," is to control and limit how much money can be spent from the Highway Trust Fund each fiscal year. The goal is to ensure that spending does not exceed the revenue generated for the fund, promoting fiscal responsibility and sustainability in transportation funding. Key provisions of the act include a strict cap on federal spending for highway and highway safety construction programs. Each year, the total obligations allowed will be based on the net receipts estimated by the Secretary of the Treasury.