FALMOUTH — Back when the Falmouth Road Race was a year-old toddler, Tommy Leonard vowed that he’d take a swan dive off the Bourne Bridge if the race didn’t attract 500 entrants. “With the way traffic is now, probably a lot of people would have liked to see me do it,” the event’s founder joked during the run-up to the 41st running of what long since has become a supersized summer fixture on the Cape.

Forty years after the race began as a bar-to-bar jaunt to mark Leonard’s 40th birthday, a field of 12,800 covering the waterfront, from kids to Kenyans, will answer the bugler’s call Sunday morning at the Woods Hole drawbridge for the 7-mile seaside scramble to Falmouth Heights. “I don’t know if this is the third running boom or the fifth running boom or if this is a running boom at all,” mused race director Dave McGillivray. “But a lot of people want to run in these things.”

As it is the organizers have to turn away nearly 5,000 applicants rather than have everyone mark-time marching along the two-lane blacktop. Next year it’s likely that the race, which will return to the third weekend in August, will start as early as 8 a.m. if ferry and church schedules can be worked out. “It would be helpful to the town because we could be cleaned up and out of everyone’s way,” says board president Scott Ghelfi.

That wasn’t a problem in 1973 when 92 fun runners sloshed through a “baby monsoon” on a Wednesday afternoon from the Captain Kidd to the Brothers Four where Leonard worked the bar and a Central Michigan student named David Duba, who’d heard about the race from a hitchhiker, won a trophy that he happily would have traded for the runner-up wristwatch.

The next year Bill Rodgers turned up after Leonard promised him that girls in bikinis would be handing out water, won a Waring blender, was hailed in the Globe as “Will Rogers” and had his car towed. Then came Olympic marathon champion Frank Shorter, then Joan Benoit Samuelson, followed by the rest of the macadam elite. “It became the central road race in America, where you came to do your best,” said Rodgers, who won it three times.

Once prize money was offered the Kenyans turned up in force and have dominated for more than two decades. If form holds they’ll again sweep the men’s and women’s titles behind former champ Micah Kogo and Joyce Chepkirui, who did it last weekend at the Beach to Beacon 10K in Maine.

If the race were to offer appearance money in addition to the $10,000 winner’s payout the elite field likely would be deeper, although the date usually conflicts with the biennial world outdoor track championships which siphons off top distance runners. “The first thing you have to ask yourself is, what do you want to be?” says McGillivray, who also is race director for the Beach to Beacon, the Boston Marathon, and more than 30 other races and walks.

Falmouth wants to stay what it has been, a quirky hybrid that lets second-graders lace up with Olympic medalists and gives back to the community. Every resident is offered a starting bib (about 2,000 accept) and the profits go back to the town, helping fund everything from playgrounds to sports teams to college scholarships to the senior center, with half a million dollars earmarked for a new all-purpose field at the high school. “We’re hoping to relay the message that we are giving back in a substantial way,” said Ghelfi, a townsman who ran his first race in 1978 in a pair of Pro Keds and went on to run for the high school and the University of New Hampshire.

The proceeds, enriched by a 10-year sponsorship with New Balance, come at a price — congestion and street closures during a peak summer weekend. This year in the wake of the Boston bombings, security will be ramped up as well. Runners won’t be allowed to be dropped at the start by car or boat and have been told not to bring bags or backpacks with them. The Beach to Beacon also took extra safety precautions, as have many other road races. “When I saw the tightened security, I thought it is quite more safer,” said Kogo, who was runner-up in Boston and intends to return next year.

The everybody-on-the-bus policy should make for smoother logistics, which is the first thing that McGillivray and his team (”I am more the conductor than a director”) tackled when he took the job two years ago. He’d run the race numerous times, including half a dozen consecutive jaunts in a downpour to celebrate his 45th birthday in 1999, and former race co-director Rich Sherman had hired him to do an “operational audit” one year. “These aren’t criticisms,” McGillivray said in his follow-up report. “They’re observations.”

Most of which McGillivray has or will be adopting as well as a separate start for the elite women this year. The challenges for any race anywhere, he says, are time and space and they’re more daunting here where the course is narrow from beginning to end and is all hills and twists. As layouts go Falmouth is like the Wild Mouse at the old Paragon Park at Nantasket Beach, with abrupt ups and downs and 90-degree turns. “I always facetiously say, if I find the people who laid out the Boston Marathon course, I’m going to wring their necks,” said McGillivray.

Falmouth was designed to finish at a hilltop tavern that no longer exists. In 1973 this was a surf-and-suds mecca for Boston-area collegians and postgrads who rented houses and cottages and partied at the Brothers, the Oar and Anchor, and the aptly-named Hunt Club. “The Heights was Party Central,” recalls Ghelfi. Now Falmouth is about families and tourists, which is why town leaders asked race organizers for a later date next year. “The road race has always been the unofficial end of summer,” said Ghelfi, who owns a candy and ice cream shop on Main Street. “As a businessman I’d like to squeeze out another week.”

When race officials polled the runners, 80 percent replied that the date change didn’t matter. If it’s August, they’re drawn to the drawbridge. “There are certain races that are special and this is one of them,” says Rodgers, who’ll take the line along with Shorter and Samuelson as he usually does. “It’s on my list every year. It’s a must-do.”

Rodgers and Shorter are 65 now, the same age that Johnny (The Elder) Kelley was when he ran the first Falmouth and finished 17th. Leonard long has outlived his original bar. “I like this event called life,” he said on Friday from his perquisite perch at the Quarterdeck Restaurant downtown. “I never thought I’d see 80. Any year over 25 is a dividend for me.”