ACDs were installed in January 2001 in a section of Northeast Frontier Railway after successful trials.
Even though there have many major accidents since then, the railways are yet to install ACDs in all trains.
The train accident in Tamil Nadu last night could have been prevented had there been ACD installed in those trains, said a senior Konkan Railway official.
ACD is designed to prevent various types of train collisions like head-on, side and rear-end collisions and those caused due to infringement by derailed vehicles on adjacent tracks.
The official said "it is a known fact that more than 50 per cent collisions on railways were caused by lapses of loco pilots who are one of the most stressful lot, necessitating technical aid to them for preventing collisions."
In the Railway Budget 2010, the then Railway Minister Mamata Banerjee had announced safety mesaures.
"To make railways safer, anti-collision devices (ACD) and Train Protection Warning Systems (TPWS) are proposed to be installed. While ACDs are already installed in the NF Railway, it will be expanded to three more zonal railways. The TPWS pilot project spanning 828 route-km will be implemented this year," according to the Budget proposal.
Also, automatic fire and smoke detection system were proposed to be installed in 20 pairs of long-distance trains in the rail budget.
Currently, the ACD is in operation on 1736km route on non-electrified section of North Frontier Railway from 2006.
Based on the experience of the NF Railway to improve reliability and dependability of ACDs and to test its functioning on multiple lines as well as electrified routes, the specifications and design configuration were revised and the system as evolved was tried on electrified multiple lines automatic signalling section of Southern railway in 2010-11.
"There were some operational and technical problems noticed in ACD trials in Southern Railway zone. These are being looked into and a new ACD version-II is being developed to suit the needs of Indian Railways," said a senior Railway Ministry official involved with safety.
He said ACD installation have been sanctioned on Northeast Frontier, Eastern, East Central, East Coast, South Eastern, Southern, South Central and South Western railways covering 8486 km.