DENVER -- A portion of I-25 will be shut down near Invesco Field Thursday for security purposes, during Sen. Barack Obama's acceptance speech. Ditto for parts of Colfax and Federal near the stadium.

Because cars will not be allowed in the stadium parking lots, many people are wondering how they're going to get to the stadium.

Their options: walk, ride a bike or take the bus or light rail.

RTD plans to operate two special shuttles between downtown and the Invesco Field.

The transit agencies regular buses are already packed.

"We've never seen them so busy," said passenger Priscilla Roberts. "But it's fun because we've been able to answer questions from visitors and help them learn their way around downtown."

"I came here to soak up every possible experience," said Julie Dahl from Sacramento. "If it takes a little longer to get to the stadium, so what?"

Dahl told 7NEWS she wants to hear Obama's speech. "I will get up an hour earlier if I have to."

Dahl will be able to ride a bus or take light rail to the stadium.

"We'll have two special shuttles running to the Invesco Field event," said Scott Reed of the Regional Transportation District.

Reed said one of the shuttles, using school buses, will run from lots A, B and C at Coors Field to 5th and Walnut across from the stadium.

The other, using RTD buses, will run down Broadway with regular stops from 22nd and Blake to 8th Ave., then to Zuni and up to 13th and Decatur.

"If you're going to take the shuttles keep in mind that the last one leaves the parking lots at 2 p.m.," Reed said. "If you have leave later than that your best bet will be to take light rail."

Reed said that regular commuters will also be using light rail.

He said the shuttles are free, but it will cost $5.00 to park in the Coors Field lots.

Reed said regular fares will apply to light rail.