The department is also the nodal agency of the state government for projects implemented by the Indian Railways as well as Department of Railways, the department of communications and the civil aviation of the Government of India.

[1][2] The commissionerate of transport (State Transport Authority) and Tamil Nadu motor vehicles maintenance department function under the department.

[3] It is also responsible for managing the licensing and permits for private buses.

[3] MTC is responsible for public bus transportation in Chennai.

[3] The department also manages the following undertakings:[4] The motor vehicle maintenance department is responsible for the maintenance and repair of all government owned vehicles including that of the chief minister.