From GMM

Even amid the latest speed-bump, organisers insist they are still on schedule to host Austin's inaugural US grand prix late this year.

Circuit of the Americas backer Bobby Epstein is being sued by race founder Tavo Hellmund, but he did not want to talk about it whilst giving the Culturemap Austin publication a tour of the construction site.

Photo released on March 3, 2012. (Photo: Circuit of the Americas)

"I'm not going to do that," he said.

What he was willing to do was insist that the circuit is pretty much "on schedule" for its mid November grand prix date.

"It's not so much a question of whether the construction will be complete," said Epstein. "It's really a matter of deciding whether to add another shift of workers and get onto a 24 hour schedule. We'll need to do that if we get a lot of rain. If it stays dry, we'll be fine."

In an official statement, Circuit of the Americas added: "Our focus remains positive. We are creating the most incredible entertainment and racing venue in the world, construction is on schedule and seat license and suite sales are very strong."