Responsible, Better Understanding of Infrastructure Leveraged Dollars Act or the Responsible BUILD Act This bill establishes the Office of the Special Inspector General for Infrastructure Projects within the Department of Transportation (DOT). Specifically, the office shall provide for independent and objective (1) supervision of certain infrastructure projects; and (2) leadership and coordination of, and recommendations on, policies designed to promote efficiency and effectiveness and to prevent and detect waste, fraud, and abuse related to such projects. The office must submit quarterly reports to Congress and DOT on state spending of infrastructure funding.