Thousands of runners and walkers are expected to fill the streets of downtown Miami on Thursday for the annual Lexus Corporate Run.

The 3.1-mile run/walk will begin at 6:45 p.m., and both start and finish at Bayfront Park. Event organizers estimate that about 18,000 participants will take part this year.

Before the event begins, there will be street closures.

Street closures

Traffic changes will begin as early as 3 p.m. on Thursday.

On Biscayne Boulevard, northbound traffic will be shifted into two southbound lanes starting at Southeast 1st Street and continuing north to Northeast Fourth Street, and vehicles will be permitted to reenter the northbound lanes.

Southbound traffic will be reduced to two lanes beginning at Northeast Sixth Street and will continue traveling south.

A full closure of Biscayne Boulevard between Southeast Third Street and Northeast Sixth Street will begin at 6 p.m. and remain in effect until about 11 p.m. Progressive road closures throughout downtown Miami are expected between 6 and 8 p.m.

Drivers will be able to access PortMiami from Northeast Fifth Street, but organizers are urging them to use the PortMiami Tunnel from I-395 to avoid congestion

Drivers traveling in or near downtown are advised to use alternate routes.

Race course

The Lexus Corporate Run route includes the following streets:

South on Biscayne Boulevard using northbound lanes to Southeast 3rd Street

U-turn onto Southeast 2nd Street

West on Southeast 2nd Street

North on North River Drive

East on Northwest 5th Street

North on Northwest 6th Avenue

East on Northwest 6th Street

South on Northwest 5th Avenue

East on Northwest 5th Street

North on Northwest 4th Avenue

East on Northwest 6th Street

South on Northwest 3rd Court

East on Northwest 3rd Street

South on Biscayne Boulevard using northbound lanes, finishing at Northeast 2nd Street

Officials urge residents, commuters and visitors to plan and allow extra travel time during the event.

Portions of this story were created with the help of a generative artificial intelligence tool. An NBC6 editor reviewed the story.