A tunnel is a structure shaped as a cave made through digging mountain, sea and river for the passage of rail way and roads. Even as of tunnel, there is a risk of various accident.

Any tunnel is vulnerable to ventilation in its structure enough to cause massive loss of lives. Underground tunnel in which trains or subways pass as well as road-shaped tunnel also may cause to massive loss of lives upon occurrence of the fire.

The part of entrance and exit of tunnels may easily cause an accident due to limit on sight as dangerous section and may cause much bigger accident when the road is frozen in winter. DTS temperature monitoring system sets alarm on the condition that icy roads are formed as advance preparation and may be much helpful in preventing accident with connection to other systems.