The start of yesterday's 100th Boston Marathon had the makings of a nightmare. Instead, it turned out to be a dream come true.

Incredibly, the race went off virtually without a hitch. The monstrous crowds race directors and Hopkinton town officials feared stayed away. The thousands of "bandit" runners who could have threatened the flow of the race never showed.

A million things could have gone wrong. Few did.

"I couldn't be happier," technical coordinator Dave McGillivray said moments after watching the last of some 38,000 runners cross the start line about 30 minutes after the noon start.

"It just went off so well. It was awesome."

McGillivray had good reason to be happy. The spectator turnout not only was smaller than expected, it was even smaller than for past marathons.

Credit must go to race directors, who in the weeks before the race made it clear there would be no room for those wishing to make the trip to Hopkinton.

But just in case the crowds did get out of hand, officials were ready.

The Boston Athletic Association had 2,000 of its 10,000 volunteers in Hopkinton to augment a formidable police force of more than 700 officers representing 40 departments from across eastern Mass. The national guard had 200 uniformed members near the start line.

Asked if he was surprised the start went so smoothly, Hopkinton police chief William McRobert was honest.

"I sure am," he said. "Hopefully, it was because we told them there was no room, don't come, and they heard it."

McRobert said he was expecting more than 100,000 people, including runners, bandits and spectators, to descend on the small town of around 10,000.

"It just never materialized," McRobert said.

"It's not nearly as large as I anticipated," said fire chief Richard Macmillan. "People knew we would have our hands full."

Among those thankful for the smaller-than-expected turnout were area businesses. While local merchants were pleased with the money the Marathon brings in, a crush of people would have been more trouble than it was worth.

"I'm glad there aren't so many people out here," said Laurel Ryerson, owner of Hopkinton Gourmet, a coffee shop on Main Street less than a half-mile from the start.

"It's been a steady flow, but I like the fact people aren't budged in around here."

It got tight in the minutes before and after the starter's gun went off, but for the most part, the crowds moved freely down the streets and on the walkways next to the runner corrals.

There was also no car traffic to contend with. All town roads were closed at 6 a.m.

While officials were happy with the way the day went, that doesn't mean they want to go through it every year.

Asked if he learned anything from this year's Marathon, McRobert said, "Yeah, to be smaller. We're not going to have another one this size again."