Search for “maximum travel distance.” Using the PDF, you find that for a tunnel without a sidewalk, emergency exits must be no more than 250 m apart. Your design will include a cross-passage every 200 m.
: Tunnels less than 90m (300 ft); the standard generally does not apply. Search for “maximum travel distance
If you are designing or inspecting to NFPA 502, also review: also review: If a fire occurs
If a fire occurs, how do people get out? NFPA 13 for sprinklers
Lists other codes you will need (e.g., NFPA 13 for sprinklers, NFPA 72 for fire alarms). The PDF links directly to these.