The 2004 NFPA 502: Standard for Road Tunnels, Bridges, and Other Limited Access Highways provides guidelines for the construction, operation, maintenance, and fire protection of limited-access highways, tunnels, bridges, elevated highways, and air right structures.
NFPA 502 has been revised to include:
New provisions for analysis of the protection of concrete and steel structures
Clarification of the use of CCTVs for automatic fire detection
New requirements for emergency lighting and illumination of the tunnel roadways
New language to focus on tunnel security issues
Updated Annex material for Fire Data for Typical Vehicles