Friday is expected to be the busiest day yet at the U.S. Open, with about 25,000 spectators expected to make their way to Shinnecock Hills Golf Club.

Organizers say roughly 20,000 fans attended Thursday, but larger crowds are anticipated as the championship heads into the weekend.

Earlier this week, some East End residents raised concerns about crowded LIRR trains and traffic backups on local roads. With the arrival of the weekend, tournament traffic is now mixing with the usual summer crowds, creating another busy day for travelers heading to and from the course.

Many fans are getting an early start, taking trains, riding shuttle buses and finding other ways to avoid congestion.

While spectators say the excitement surrounding the U.S. Open makes the trip worthwhile, some say transportation has been the biggest challenge of the week.

Officials expect heavy crowds to continue through Sunday and say they are prepared for one of the busiest stretches of the tournament as visitors continue pouring into the East End.