SUPERIOR, Ariz. — A highway tunnel on U.S. 60 east of Superior is being closed to traffic nightly this week for installation of new lighting that the state Department of Transportation says will save energy and improve visibility.

ADOT says a five-mile stretch of U.S. 60 that includes Queen Creek Tunnel will be closed in both directions between 10 p.m. and 4 a.m. nightly through early Friday morning.

Suggested alternate routes include taking State Routes 77 and 177 between Superior and Globe and taking State Routes 87 and 260 through Payson.

The department says the new light-emitting diode, or LED, system will adjust the lighting level based on ambient light and weather conditions outside.

A $1 million federal grant is helping to pay for the project.