Beginning next week and continuing through November, the eastbound 91 Freeway in Corona will be shut down overnight, three days a week, for work on an interchange improvement project.

The nighttime closures are set to get underway Monday, Oct. 16, with all eastbound 91 lanes out of service from Green River Road to Serfas Club Drive, on the west end of Corona.

The lane closures will be in effect from 11 p.m. to 5 a.m. The same closures will be implemented again on Tuesday, Oct. 17, and Wednesday, Oct. 18, according to the Riverside County Transportation Commission.

The agency said that the Monday-to-Wednesday schedule will be maintained, weather-permitting, until Nov. 30.

In addition to the general-purpose lanes, the two toll lanes on the eastbound 91 will be shut down at the same time.

The closures are required for the 71/91 Interchange Project, which entails replacing the current single-lane connector from the eastbound 91 to the 71 Freeway with a two-lane connector loop, which will facilitate a larger volume of vehicles at one time, reducing congestion.

The $137 million project began in February.

A commission statement said the nighttime closures will “allow crews to safely construct support structures for the new connector.”

The Green River Road on-ramp to the eastbound 91 will also have to be shut down for traffic safety during the work.

Commission officials recommend that motorists avoid the eastbound 91 during the overnight hours Monday, Tuesday and Wednesday, starting next week, and instead use the 60 Freeway to the north as an alternate. Otherwise, traffic will be crammed into a single lane, taken off the freeway at Green River Road and funneled through the city to downtown, where drivers can rejoin the eastbound 91.

Along with expanding the connector itself, the project will also involve adding an eastbound auxiliary lane to the 91 and realigning the Green River Road on-ramp. The expressway, too, will be realigned to create space for the new connector.

Officials said that a wildlife crossing will be one of the other features of the reconfigured interchange.

The project is expected to conclude in 2025.

More than one-third of the project funding — $58.1 million — is being provided by the California Road Repair & Accountability Act of 2017, which hiked gasoline taxes to pay for infrastructure and other projects. The county’s Measure A revenue, which is generated by a half-cent sales tax, is also covering a share of the expense, while federal and other sources make up the difference.

Project information: www.rctc.org/71-91interchange