As Bay Area residents ready themselves for the 100th anniversary run of Bay to Breakers — and all the costume-wearing, float-riding debauchery the annual race usually includes — at least one San Francisco family is preparing to participate in their own traditional way: as an intergenerational family affair.

Benjamin Schneider with grandfather Alvin Siegal in last year’s Bay to Breakers.

“I’ve been looking forward to it since last year,” Alvin Siegal, 87, said by phone from Cleveland. Just like last year, he planned to fly out a few days before the race, which takes place Sunday, May 15.

Bay to Breakers, one of the world’s largest and oldest footraces, takes runners from the bay side of the city, near the Embarcadero, to the Great Highway near the breakers at Ocean Beach. The 7.5-mile course cuts through downtown, Hayes Valley, the Panhandle and Golden Gate Park. Siegal will walk the race with his stepson, Kirk Schneider, a San Francisco psychologist, and Schneider’s 16-year-old son, Benjamin.

An experienced runner who didn’t start racing until his 50s, Siegal has run 23 marathons over a 20-year period (17 in New York City, six in his hometown of Cleveland), as well as “300 or so” shorter races, by his estimate.

“I have a lot of T-shirts,” he said with a chuckle. “I try to give them away.”

The retiree — who owned a mortgage banking company for many years and, with his wife, endowed the Laura and Alvin Siegal College of Judaic Studies in Cleveland — stopped participating in races as a competitive runner when he was 72. He still does events for fun, and he exercises regularly and eats well to stay fit, he said.

But Bay to Breakers holds a special place in his heart, said Siegal.

“I love the different costumes people wear, everything there is to look at while you’re walking,” he said. “And just the sheer amount of people — I’d never seen anything like that.”

Grandson Benjamin Schneider, who attends Lick-Wilmerding High School in San Francisco, said it’s nice to be able to participate in such a unique day with his family.

“I’m not a runner, exactly — I play basketball,” said the Brandeis Hillel Day School graduate. “But it’s a really fun day, and I think it’s cool that my grandpa’s so excited by it.”

“I just think it’s a wonderful walk,” said Siegal, who added that he hopes the family tradition will continue for a long time. “I’ve been to a lot of walks, but it’s a special one. Not to mention, I love the city. Nothing comes close to San Francisco.”