"To run this schedule week in and week out, week in and week out, it's more demanding than it used to be," Rudd said at Michigan International Speedway, where NASCAR was still trying to run the rain-delayed 3M Performance 400 on Monday.

"I think it's really a young guy's sport, a single guy or a guy that's married or no kids, which means a guy in his 20s or early 30s," Rudd said. "Because there's so many demands on your schedule that I guess I'm not willing to want to make the sacrifices for that full-time schedule any more."

Rudd, whose birthday is Sept. 12, said he plans to retire at the end of this season.

He drove in a record 788 consecutive races from 1981 through 2005 before sitting out the 2006 Nextel Cup season. But Rudd said he purposely never used the word retirement at that time.

"At the end of 2005, I wasn't sure if I wanted to retire or not, so I never made a statement," he said. "I took a year off and I ended up coming back. It's clear to me what I want to do now.

"It's a great sport and it's been good to me, and we've still got 14 races left (this year). But the grind of the schedule just kind of wears you down."

Rudd came back this season to drive for what is now Yates/Newman/Haas/Lanigan Racing after Robert Yates asked him to help him out of a tough situation. Yates had lost driver Dale Jarrett and his high-dollar UPS sponsorship to the new Toyota team of Michael Waltrip and needed a name driver to replace the 1999 Cup champion.

Rudd joined second-year driver David Gilliland at RYR and both have struggled this season, with the 31-year-old Gilliland 28th and Rudd 29th in the points and only one top-five and three top-10s between the teammates.

Asked if he might feel different about continuing in 2008 if he was in the top 10 in points, Rudd said, "I might. I've always been motivated by performance, and everybody in this garage is pretty much the same way.

"We really haven't had those this year. We've had one top-10 _ a seventh at Charlotte."

Rudd said he doesn't want to blame the Yates team, though.

"When I came back over here, this team had sort of hit rock bottom and it was in a rebuilding process," Rudd said. "And it's coming along _ slowly, but it's coming along. The merger with Carl Haas I see as a big plus."

Yates recently announced a partnership with Champ Car's elite Newman/Haas/Lanigan team that is expected to be an engineering bonanza for the stock car team.

"Right now they're on the bottom rung of technology and they can quickly move to the top rung," Rudd said. "If I was in my 30s, somebody like David Gilliland, this would be a great opportunity. If you can wait it out, it's going to eventually work its way back to where it used to be.

"This sport has always been a tough sport, but the enjoyment has come from winning a race or running up front, in the top five or top 10. That's sort of the benefit you would receive for the demands on your time. We haven't had many rewards this year to offset some of that."

Rudd said he doesn't know what he will do next year or beyond that.

"I guess I want to be a little lazy for a while, but I don't really know what the future holds," he said. "I'm very fortunate. When I came into racing, there was no money and I saw it to the point where guys are making good money and, financially, I was able to put aside so I don't have to worry about taking the first job that comes up.