DAYTONA BEACH, Fla. (AP) — NASCAR's most famous race track is seemingly safer and possibly more politically correct as the series returned to its birthplace Friday.

Daytona International Speedway, in the final push of a $400 million renovation, has come close to covering the speedway in energy-absorbing SAFER barriers as track President Joie Chitwood vowed to do after Kyle Busch was injured in February.

Busch, who broke his right leg and left foot when he crashed into a concrete wall a day before the season-opening Daytona 500, made his return to the speedway Friday and promptly wrecked in an 11-car crash minutes into the opening practice session. His February crash prompted safety upgrades across NASCAR, particularly at Daytona.

Chitwood said the track installed 4,100 feet of SAFER barrier since Busch's crash. The soft walls were installed beyond the exit of pit road, the exit of Turn 4 at pit entrance and the entire inside wall along the backstretch.

"With this being a high-speed property and with all the cars traveling close together, the feeling is we want to (be) safer everywhere," Chitwood said.

Chitwood had initially promised the night of Busch's accident to install the SAFER barriers "on every inch of our property," but the speedway did not have time to complete the project before Sunday's race. Chitwood said the remaining 4,000 feet will be installed before NASCAR returns next year for the Daytona 500.

The track also added more than 200,000 square feet of asphalt in four locations: inside the grass area at Turn 1, the exit of Turn 4 and two areas at pit-in and pit-out, and it realigned the wall that Busch hit head-on. Busch was injured when he spun late in the race then slid through the grass directly into a concrete wall.

Drivers can't control their cars when they hit the grass at a high speed, but asphalt is easier for a driver to regain control. Busch, who unwittingly became the face of a push for more SAFER barriers at all tracks, last week called on the facilities to remove the grassy areas around the speedways. He made that request after Ryan Briscoe's car went airborne when he hit the grass in Fontana, California, during last week's IndyCar race.

Daytona paved more than 177,000 square feet of grass in the Turn 1 area where Busch slid.

"From a paving perspective, that was part of an element in the analysis of the incident from February in terms of the ability to slow down or turn," Chitwood said. "The feeling in that area, due to the high-speed nature and where that accident occurred, was that asphalt would be a better solution for the drivers and the ability to control the incident."

Meanwhile, Chitwood made Daytona the first track to distance itself from the Confederate flag in advance of its weekend of racing.

NASCAR chairman Brian France last week called the flag a symbol he finds offensive and said he wants to be as aggressive as possible in barring it from sanctioned events. The series also said it bans the flag from official use at its events.

Chitwood then said he was offering an exchange program in which fans could trade a Confederate flag for an American flag this weekend. The flags are available as RV's enter the Turn 1 tunnel, but Chitwood said Friday he was not aware of any swaps occurring yet. This weekend's races are the first in the South since the mid-June attack that left nine black churchgoers dead in Charleston, South Carolina. The suspect had embraced Confederate symbols, including the battle flag.

There were a handful of Confederate flags flying in the infield Friday, the opening day of practice at Daytona. NASCAR's roots are in the deep South and the series hosts 18 Sprint Cup races in Alabama, Florida, Georgia, North Carolina, Tennessee, South Carolina, Texas and Virginia.

"I think the voluntary exchange program for us right now was appropriate with the limited window that we had coming into this event weekend," Chitwood said. "And more importantly, I think it's important to trust our fans, asking our fans to display a flag that we should all be proud of. Everybody should be proud of the American flag."

After Daytona's offer to exchange flags, it was one of 30 tracks that host national NASCAR races to unite in asking its fans not to fly Confederate flags.

"We are asking our fans and partners to join us in a renewed effort to create an all-inclusive, even more welcoming atmosphere for all who attend our events," the tracks said in a statement. "This will include the request to refrain from displaying the Confederate flag at our facilities and NASCAR events."