Catie Neumann cheered on runners from the sidelines in Washington Square.

"I feel safe," Neumann said.

She was drenched and cold and miserable. But it was important to her to be there.

"Last time I was here was two years when everything happened so I wanted to kind of come back out,” she said.

Neumann's friend, John Lagedrost, says it’s good to give people a sense of security.

"Some might say it’s overkill but you know, especially on a day like today, you need to get people out there, the bad weather, and it’s a good way to guarantee people feel safe when they come out,” he said.

Those who mention overkill may have visited the start or finish lines, where people with bags were turned away. In Copley Square, some blocks had three checkpoints where bags were searched and tagged. The numerous yellow jackets of officers were bright spots of color in an otherwise dreary day. The Massachusetts Emergency Management Agency says it was all carefully planned — dozens of agencies and multiple jurisdictions worked together and pulled it off without incident.

Eric Johnson, a project manager at Lan-tel Communications of Norwood, which runs cameras across the city for the Boston Police Department, was at a command center at the Boston Public Library, and says nothing really suspicious happened.

"I’m sure that there were some incidents but nothing that we heard or saw that was very significant,” he said.

Also at the command center was Mike Driscoll of DVTEL, which supplied software to analyze incoming video for suspicious behavior. He isn’t sure the software could’ve prevented the bombings two years ago.

"A lot of times when you make stronger security measures, you’re doing that to be proactive, but you’re also making it to deter anybody from possibly trying to carry something out,” he said.

Surveillance cameras were one of the ways law enforcement kept much of its security presence out of sight. Greater Boston Track Club distance coach Rodney Hemingway ran the race and says that made a big difference for him.

"That was one less thing you had to consider," he said. "You knew they were there, you could see them once in a while. But they weren’t all over the place like they were locking down an army base."

Hemingway says security, or the lack of it, only became a problem once he crossed the finish line. For him, by the way, that was in 2:46:57 — a 12-minute best over last year. He says there were no police to direct runners and some walked into streets, not realizing that they weren’t blocked off to traffic.

"It was a little scary because people were in such a daze from finishing and so cold, that they didn’t realize traffic was not stopping," he said. "And people had some really close calls."

Hemingway says he had to walk a half hour to pick up his bag —the last thing he wanted to do after running a marathon. He says runners waiting in the long line exhibited signs of hypothermia, but they were far from medical personnel.

"Logistically, it makes sense, from a security point of view, and also, I guess, logistical for the finish line not getting backed up, so they were spread out, but I really hope they find another location,” he said.

The event will change and adapt, says Tom Derderian, who detailed the history of the race in his book "Boston Marathon." He says the marathon has a history of evolving.

"Initially it was a contest of young men of military age proving how tough they are," Derderian said. "And now it’s a celebration of human fitness and it’s an occasion for fundraising."

He says the new security level is just the marathon adapting to contemporary reality, for better or worse.

"Was there anyone who planned to do something at this event today, who was deterred because of the security? Who knows?" he said. "We’re stuck with providing security because of something that might happen, that’s highly unlikely to happen — but it did happen once, so it could happen again, and there were are.”

As long as terrorism remains a possibility, Derderian says we’re probably stuck with this level of security.