With the U.S. Open coming to the Merion Golf Club in less than five weeks, public safety officials are more worried about road congestion and lost drivers than crime or terrorism.

"Our biggest concern is traffic," said Haverford Township Deputy Police Chief John Viola. "If we have traffic issues, it ties everything up and then it becomes a security issue on top of that."

The township, home to the club hosting the tournament June 10-16, has published road closures and detours, and held town hall meetings to answer residents' questions. The United States Golf Association, anticipating 25,000 to 30,000 spectators a day, is urging people to take trains whenever possible and providing shuttles to and from a remote parking lot.

But with street closures expected to displace about 24,000 cars a day, problems will inevitably arise.

"Saturday and Sunday are going to be the worst, obviously, because it's a family day," said Steven K. Lindner, a Lower Merion Township commissioner whose ward borders the club. "You're going to have certain events that are happening on those days even if the Open weren't here."

Indeed, the tournament overlaps with the final week of school for Haverford district students, a high school graduation, and Father's Day - not to mention the thousands of commuters who use Haverford Road and Ardmore Avenue every day.

While traffic headaches may be unavoidable, Viola says he is confident he has other public safety issues in hand. His department has spent two years preparing for the event.

In recent months, other law enforcement agencies have joined in, including the Department of Homeland Security, the FBI, the U.S. Postal Service, and the Bureau of Alcohol, Tobacco, Firearms & Explosives. Delaware County municipalities, Lower Merion, and Philadelphia will also provide officers to patrol the tournament, with the USGA paying the bill.

In addition to uniformed officers, the USGA is contracting with private security firms to check spectators' bags and support police with extra "eyes, ears and radios," Viola said. USGA staff, Merion Golf Club staff, and event volunteers have been trained to report anything suspicious.

Delaware County's 911 dispatchers will set up a command center at Ardmore Avenue and Darby Road, and Viola said every local law enforcement agency would have a representative on site. A public safety hotline will route calls directly to the command center, keeping 911 lines clear in Delaware and Montgomery Counties, Viola said.

After the Boston Marathon bombings, Viola reviewed the plan with the USGA and other law enforcement agencies. "We were confident that our coverage was adequate," he said.

The U.S. Open is easier to secure than a marathon because the course is gated and ticketed and crowds are smaller; the Boston Marathon had 23,000 runners and about 500,000 spectators.