Phil Mickelson shares a smile during a practice round this week at Shinnecock Hills in Southhampton, N.Y. (Warren Little/Getty Images)

There will be heavy traffic at this U.S. Open. Tiger Woods’s yacht is jammed in here along with all of the Lexuses, which are lined up thicker than the shingles on Shinnecock’s quaint Victorian clubhouse. Traveling by “the dinghy,” as Woods refers to his 155-footer, turned out to be a smart move, because funneling 156 golfers and all that comes with them into a dated summer resort area accessible only by farm lanes has caused gridlock. And the crowds aren’t even here yet.

The real traffic jam will be on the golf course, with a pileup of contenders ranging in age from Phil Mickelson, who turns 48 this week, to Jordan Spieth, 24. Mickelson is trying to complete a career Grand Slam, and the 42-year-old Woods is trying to win his first major in 10 years, and between them and the trophy is a throng of great players under the age of 30, with just about all of them playing well at the same time as they cruise toward Shinnecock Hills, the fine old par-70 artifact that has trouble all over its sandhills, and a history of producing close finishes. There will not be much room for separation. “The way you get in trouble here is you anticipate too much, and you get too far ahead,” Mickelson says.

Has a major championship ever offered such a classic generational confrontation? “Certainly, we’re on the back ends of our careers,” Woods says frankly of him and Mickelson. It’s such an interesting juxtaposition that the USGA couldn’t resist crowding them together for the first two rounds: Woods will play in a threesome with those two dualists for No. 1 in the world, Dustin Johnson, 33, and Justin Thomas, 25; Spieth will be with Mickelson and 29-year-old Rory McIlroy. Try to find a guy in those threesomes who is playing badly.

“The game, I’ve got a lot of confidence in my game right now,” says Johnson, who won last week with his walk-off eagle at the St. Jude Classic. That gave him the No. 1 ranking over Thomas, who had held it for all of four weeks. “He deserves it,” says Thomas, who adds pointedly, “for the time being.”

That’s the speed at which things move with this young crowd, all of whom came up together. “It almost feels like I’m back in high school and college,” Spieth says. “These are the same guys we used to battle it out with then, and I’d win one, then they would win one, then they’d win one. You know, it’s just blown up now . . . . And then these same friends are able to get out here and compete on the highest level against, you know, your Tigers and Phils that are here that we grew up idolizing.”

The only one who might be said to be slumping at the moment is Spieth — if you consider four top-10s and a final-round 64 at the Masters to be a down year. But after fighting off a case of mono that cost him some practice time, he says he’s got his equilibrium back. “I feel like my game is in the best shape it’s been in a long time,” he says. “And my results don’t necessarily speak toward that, but I feel that way, and so I’ll stick with the process, and they’ll surely come at some point.”

What you hear in that statement is the luxury of youth — what adult gets mono? — and the assurance of someone who’s got many seasons ahead. And who doesn’t know just how much disappointment can await a phenom. Spieth was just a year old when then-24-year-old Mickelson tied for fourth in the 1995 U.S. Open here behind Corey Pavin, after the par-5s suckered him into being too aggressive. And he was just 10 in 2004, when Mickelson finished second to Retief Goosen by double-bogeying the 17th hole. Was that the worst one that got away? “I can say that a few times about this tournament,” Mickelson says.

Just last season it seemed that a generational handoff had already occurred. Both Woods and Mickelson were absent from the U.S. Open at Erin Hills, Mickelson to see his daughter’s graduation and Woods with the recurring back trouble that has kept him out of the tournament since 2015. They were mere television spectators with the rest of us as Thomas burned the course down with a record-tying 63 on Saturday, and then 28-year-old Brooks Koepka won by tying the overall Open scoring record Sunday.

It’s therefore an unexpected luxury to have both of them back in the field, and in such form. Mickelson would be the oldest player to win a U.S. Open, surpassing the 45-year-old Hale Irwin’s feat in 1990. But that doesn’t mean it’s impossible — not when a course suits a player like this one does, and that player comes in with half a dozen top-10 finishes this season. “Certainly the way I’ve been playing this year and at the consistency level, as well as at a much higher level than I’ve played the last few years, gives me a great opportunity,” Mickelson says. “But the last thing I’m thinking about right now is trying to win. I’m trying to get myself in position for the weekend because when you try to go out and win a U.S. Open, you will lose it quick.”

As for Woods, he looks more relaxed and comfortable at a major than in years. Though that could be a reflection of his comfortable, low-stress accommodations. Traffic on the two-lane roads into Shinnecock has been so heavy that it has taken some players almost two hours to travel 15 miles. Woods solved the problem by docking his yacht in the tiny village of Sag Harbor, an easy back-roads commute.

In Woods’s last Open, he shot 80-76 at Chambers Bay in 2015, while Spieth went on to win his first. It’s hard to fathom, but it’s been a decade since Woods lifted the trophy at Torrey Pines. “I don’t like that feeling,” he says. In between, there have been four back surgeries since 2014, substance abuse, withdrawals, a ranking of 1,199th in the world, and a lot of false starts. But there is nothing false about this one. He was a factor at Bay Hill, the Honda Classic and Memorial, and he almost won the Valspar Championship. Ask him how his life has changed, and he says shortly, “It’s better.” That is reflected in everything from his swing to his overall demeanor.

“I’ve given myself chances to win, which I didn’t know if I was ever going to do again,” he says.

That makes him viable — if he can get through the traffic, of course.