HOUSTON (AP) — IndyCar's return to Houston got off to a bumpy start.

A bump in the concrete in Turn 1 at Reliant Park delayed practice Friday while IndyCar officials erected a chicane of tires that drivers had to navigate their way around when they finally got on the course.

The race promoter planned to bring in equipment Friday night to grind down the area for a more permanent fix to the bump, which wasn't discovered until cars from IndyCar support series hit the track earlier in the day. The bump, in an area typically used to store the grass from the Houston Texans' field between games, was just past the start/finish line.

Because track construction could not begin until after the Texans' game Sunday, there was no time for an inspection before Friday and the traditional IndyCar track walk for competitors was canceled Thursday as workers completed assembly.

"A street course normally takes four to six weeks to build," race promoter Mike Lanigan said. "We did it in four days. We thought we did it right, but we missed something extremely important."

IndyCar postponed qualifying for Saturday's doubleheader opener until Saturday morning, and said qualifying for Sunday's event will be held before that race.

Lanigan brought IndyCar back to Houston and Reliant Park for the first time since 2007, with Shell-Pennzoil as the event's title sponsor.

"The lateness of the build of this project, which has been unprecedented, is really one of the pitfalls when you wait until the last minute to do one of these things," said Brian Barnhart, IndyCar's president of operations. "It's one of the challenges you face, but we've got a great solution in place and it's not going to affect us in a negative fashion toward a lot of drama for the two qualifying sessions and the doubleheader."

But there was drama during IndyCar's two practice sessions.

Championship points leader Helio Castroneves spun twice, and hit the chicane during the first practice session after Josef Newgarden ran into it and knocked it into Castroneves' path. It didn't damage Castroneves' car, but didn't make for the smoothest day.

Castroneves, who takes a 49-point lead over Scott Dixon into the weekend, was pleased track officials planned to grind down the bump and remove the chicane overnight.

"I'm happy they are going to make the fix, but what I don't like is that the people who looked at the track missed that big of a deal," Castroneves said. "Emergencies happen and we've got to be open-minded."

Ryan Hunter-Reay also suffered damage when he ran over a curb, went slightly airborne and hit the wall. He chalked it up to street course racing.

"That's the challenge with coming and putting a race track down on city streets, and in this case in Reliant Stadium's parking lot," Hunter-Reay said. "It's tough, but hopefully the grinding will be a fix."