Neb. Rev. Stat. § 60-6,126: Lane direction control signals; signs.

When lane direction control signals are placed over the individual lanes of a street or highway, vehicular traffic may travel in any lane over which a specified or appropriate green indication is shown but shall not enter or travel in any lane over which a specified or appropriate red indication is shown. When such signals are in use, signs adequate to advise motorists of the meaning of such signals shall be erected.