Jiddah, Saudi Arabia • With her husband in the passenger seat and her daughter cheering her on, Dania Alagili guided her sport utility vehicle onto the King Abdulaziz Road early Sunday, breaking a social barrier as she braved the roaring Saudi traffic.

“This is a day I’ve been waiting for,” she said. “For the last 30 years.”

Saudi Arabia allowed women to drive for the first time on Sunday, lifting a ban that was the last of its kind in the world and one that had come to symbolize the kingdom’s harsh subjugation of women.

In an effort to modernize the country and boost its economy, Crown Prince Mohammed bin Salman has eased some social restrictions. And by the standards of the Saudi Arabia, an absolute monarchy guided by an ultraconservative religious creed, even modest reforms — like the lifting of the driving ban or the opening of cinemas — are viewed by many here as revolutionary, if long overdue.

That Alagili, 47, had earned her driving license 23 years ago, in the United States, did nothing to dampen the joy on Sunday of driving in her own city, on her own roads, on her own.

Without the driving privileges, and dependent on men, “I felt heavy, tied back,” she said.

She headed to her father’s house, knowing he would want to share the moment with his only daughter. “For women it’s a big deal. And for the men who supported us,” she said.

Cars raced by on the King Abdulaziz Road, a harrowing stretch of freeway that is also an argument for re-evaluating the driving privileges of some of the men in Saudi Arabia.

“You’re doing great, Momma,” her daughter, Ahd Niazy, 23, said from the back seat. Hany Niazy, Dania’s husband, called the couple’s other daughter, Layal, 19, who lives in Washington, D.C. Her face appeared on his phone.

“Momma, how do you feel?” Layal asked.

“I feel great,” he mother said. “I feel wonderful. I am born today.”

The government’s heavily promoted celebration of the ban’s lifting included gathering female drivers near a mall in Jiddah at around midnight on Sunday. Some arrived driven by their husbands, and then took wheel themselves, setting off in a small convoy, as journalists crowded around, to explore the city’ s roads.

The scene recalled a protest, nearly 30 years ago, in Riyadh, the Saudi capital, when dozens of Saudi women gathered at a supermarket and drove around the city before they were stopped and detained. The protest was a milestone for Saudi feminists and for what would become a decades-long campaign to end the driving ban.