Tunnels & Underpasses
Tunnel signage is lit by headlights against a dark surround — Type XI plus a passive photoluminescent fallback.
Contrast against a dark surround, plus a passive fallback. Inside a tunnel the only light reaching the sign is a headlight, and the surround is black, so the sign is judged against nothing rather than against a bright sky.
NVR-11000 (Type XI) for the gantry panels, NVR-PL45 45 mm photoluminescent path marking for the walkway: when the lighting circuit drops, the path is still visible for the 90 minutes the code asks for.
Both are part of the same submission package — ASTM D4956 reports for the sign face, ASTM E2072/E2073 test data and the UL 924 listing for the egress components.
More in this section.
Highway & Expressway Signs
Overhead gantry panels read at a wide observation angle — the case for Type VIII / Type XI, not Type IV.
Work Zone Drums & Barricades
Work zone devices are read at close range and low angle — Type IV is the volume answer.
Delineation & Guideposts
A delineator is a small target repeated at speed — Type II is enough and lasts seven years.