Street closures in Downtown Houston for Trump's appearance

Deejay Miller (left) kisses her fiancée Glenn Collins, Waco, Tx, as they stay warm hours before President Donald Trump's rally Monday night at Toyota Center Sunday, Oct. 21, 2018, in Houston. Deejay Miller (left) kisses her fiancée Glenn Collins, Waco, Tx, as they stay warm hours before President Donald Trump's rally Monday night at Toyota Center Sunday, Oct. 21, 2018, in Houston. Photo: Steve Gonzales, Staff Photographer Photo: Steve Gonzales, Staff Photographer Image 1 of / 92 Caption Close Street closures in Downtown Houston for Trump's appearance 1 / 92 Back to Gallery

The Houston Police Department will be "fully mobilized" for President Donald Trump's Monday downtown rally, for which at least 70,000 people have signed up despite the venue's roughly 18,000-person capacity, Chief Art Acevedo said Friday.

Police began closing off streets around the Toyota Center Sunday evening, with closures on Bell, Jackson, La Branch and Polk streets near the arena.

BACKERS: Abbott, Patrick to speak at Trump rally in Houston

By 7 a.m. Friday, 77,854 people had signed up for the rally, according to a person familiar with the matter. Attendees must have tickets to enter and will be admitted in the order in which they line up.

"Keep in mind that once the capacity is met, you won't get in whether you have a ticket or not," Acevedo said.

Meanwhile, the Trump campaign was not considering moving to a bigger venue, the person familiar with the event said.

Trump is holding the rally with Sen. Ted Cruz, R-Texas, who is facing a re-election challenge from U.S. Rep. Beto O'Rourke, D-El Paso.

Acevedo said HPD had heard unconfirmed reports of a separate nearby rally for O'Rourke that could draw thousands more people.

"We will have many many officers out and about," Acevedo said. "We will have officers on the high ground, low ground, in the air. We will have officers in plainclothes, we will have undercover officers, we will have react teams."

He added that officers from the federal, state and county levels would lend support, with the usual Secret Service presence accompanying Trump.

The police department expects people to "exercise their First Amendment rights in a lawful manner," Acevedo said, including protesters and counter-protesters.

"You would be foolish not to," he said.

Gov. Greg Abbott and Lt. Gov. Dan Patrick, Trump's Texas campaign chairman, will also speak at the rally. Trump is set to begin speaking at 6:30.

People will likely line up overnight for the rally, Acevedo said, adding that the department expects large crowds around the Toyota Center and downtown. He advised people who work downtown to plan accordingly for delays.

The event will start around 5 p.m., Acevedo said, with doors opening two to three hours before then. The department will post specific road closures Friday night or over the weekend, he said.

Rain is expected Monday, with projected temperatures in the high 50s to low 60s.