The Detroit Department of Transportation is one of the largest public bus transit carrier in Michigan. The department maintains a work force of more than 1,500 employees. It operates a vehicle maintenance division that provides warehousing, materials management and quality assurance services. Operational for over 75 years, the Detroit Department of Transportation is also responsible for the repair and maintenance of buses and other service vehicles. The department provides management information, payroll, contract administration and risk management services. The Detroit Department of Transportation offers Scheduling, service development and accounting services. The department is governed by the City of Detroit, which also operates police, public lighting and law departments.