POTOMAC, Md. — Friends and family remembered longtime Minnesota U.S. Rep. Jim Oberstar on Thursday for his insatiable curiosity and his passion for transportation.

About 500 people attended Oberstar’s funeral Mass at his home Catholic church in a Washington, D.C., suburb, where he lived throughout his 36-year career in Congress and afterward.

Both Minnesota Sens. Amy Klobuchar and Al Franken touted Oberstar’s successful career in Congress, as did former Transportation Secretary Norman Mineta.

“We all learned from him,” Mineta said. “I loved this man.”

Franken said Oberstar, a fellow Democrat, always had a zeal for sharing what he learned about infrastructure.

“He had a tendency to go on and on, but it was because he believed everyone was as curious about the world as he was,” Franken said, “and he was almost always wrong about that.”

Oberstar died in his sleep last weekend at age 79. The son of an underground miner from Chisholm in northeastern Minnesota, Oberstar was first elected to Congress in 1974 and served 18 terms — the state’s longest-serving member of Congress. He lost to GOP challenger Chip Cravaack in 2010 as part of a Republican takeover of the U.S. House.

Oberstar was a champion for transportation safety and infrastructure improvements. He became chairman of the House Transportation and Infrastructure Committee in 2006.

Oberstar also was remembered for his beloved bicycle. Other bicyclists found it hard to keep up with him.

“We all thought dad would outlive us,” said his daughter, Noelle Tower.

“And he … believed that, too,” she added, eliciting laughs.

Oberstar’s children said he was happiest when he was amid lively family discussions or playing with his grandchildren.

“He will be remembered fondly for his ability to break into flawless French … but we will always remember him for his patience,” said another daughter, Monica Weber.