Daytona International Speedway has installed 4,100 feet of energy-absorbing soft walls since Kyle Busch's crash into a concrete wall at the famed track in February.

Speedway president Joie Chitwood says the track also added 200,000 square feet of asphalt, which scrubs speed considerably better than grass.

Busch broke his right leg and left foot in a crash the day before the season-opening Daytona 500. His Xfinity Series car hit head-first into a concrete wall near turn one, a section not covered by the safer walls called SAFER barriers.

Chitwood vowed afterward to install SAFER barriers "on every inch of our property." Daytona still has 4,000 feet to install after Sunday's race to complete the project.

Chitwood also said the Confederate flag issue is a tough one because people on both sides are passionate about it, adding that "we've really got to think through it and be fair to both sides and make sure that whatever we come up with can work."