A driver hauling placarded Division 2.3 poison gas near Baltimore sees signage prohibiting that hazard class from the Baltimore Harbor Tunnel. Which statement correctly explains why this restriction is legally enforceable?

Question

Accepted Answer

The tunnel authority's restriction functions as a state/local NRHM routing designation that must meet the federal standards in 49 CFR 397.71, and the carrier is separately obligated under 397.67 to follow it (or, absent such a designation, to avoid tunnels when a practicable alternate route exists)

Answer

It isn't enforceable — federal law never allows a state or local authority to restrict specific hazmat classes from a specific tunnel

Answer

Only the carrier itself, never a state or local authority, has legal power to designate which hazmat classes may use a given tunnel

Answer

The restriction only binds carriers that are domiciled in Maryland