National Highway 234 (NH 234), was a National Highway in India that originated in Mangalore, Karnataka, travelled through Venkatagirikota, Andhra Pradesh and Vellore, Thiruvannamalai, Tamil Nadu, terminating at Villupuram, Tamil Nadu.

[1] Under the new highway numbering system, Mangalore to Banavara part of this highway was merged with National Highway 73, Banavara to Mulbagal has been a part of National Highway 69, Mulbagal to Vellore is tagged as National Highway 75 and Vellore to Villupuram sector now comes under National Highway 38.

[2] Mangalore - Bantwal - Madanthyar - Belthangady - Ujire - Charmadi - Mudigere - Belur - javagal - Huliyar - Bukkapattana - Sira - Madhugiri-Byranahalli -Kotaladinne- Gauribidanur- Manchenahalli - Chikkaballapur- Shidlaghatta- Chintamani-Srinivaspura- Mulabagal (NH-4) - Venkatagirikota - Pernampattu - Gudiyatham - Vellore City - Kannamangalam - Polur - Thiruvannaamalai - Villupuram[3] As the forest department does not allow the widening of the roads going through the western Ghats, it is expected that a tunnel will be built, same like as proposed by Japanese consultants to the Shiradi Ghat of NH-75 (Old Number NH-48).

A tunnel will help in reducing the travel time by 3 hours, reduce the fuel usage and increase the productivity of the industries around.

It will also provide an alternative route to the large sized trucks transporting materials to the seaport and air-cargo facility at Mangalore .