Baby in a rush arrives during the rush-hour drive

Following instructions over the phone, Bonaserra stopped the couple’s silver Volkswagen Passat at the intersection of Huron and Concord avenues in Cambridge, police said.

Within minutes, Troopers Frank Parker and John Arone arrived at the scene. Parker asked Bonassera if his wife would be able to hold off on delivering the baby until she could be transported the rest of the way to Mount Auburn Hospital.

“I was kind of hoping he’d say ‘yes’ and make my life a little easier,’’ said Parker, who has been with State Police for 28 years.

But things were too far along for the expectant mother. She sat backward in the car’s passenger seat, her back resting on the dashboard and her legs propped over the reclined seat.

The top of the baby’s head was already visible.

Parker has had some experience with childbirth - he was in the room when both his sons were born - but he had never been “on the receiving end’’ of a delivery, he said. He got to work, crouching next to Nancy Bonassera and coaching her through the labor.

Meanwhile, the father paced outside the car, wide-eyed and sweating.

Arone, who said he had never been “that up close and personal’’ with childbirth, tried to assure the man that everything was going to be OK.

“He was shocked and nervous,’’ Arone said. “I remember looking at his face and it was just pale white.’’

Despite his prior delivery room stints, Parker did not have much by way of suggestions for Nancy Bonassera. “Do whatever feels comfortable,’’ he told her.

Since this was the woman’s second child, she knew exactly when to push, Parker said.

The troopers said they were both surprised by the mother’s composure and cheerfulness throughout the delivery.

She did not scream, they said, and never stopped smiling.

“I’ll be honest with you - I’ve seen people wince more when they’ve gotten in a minor fender bender or stubbed a toe,’’ Arone said.

“This woman gave birth like it was a walk in the park.’’

After just a few minutes of labor, Gabriella Bonassera was born at 8:09 a.m.

“It’s just such a good feeling,’’ said Parker, who helped guide the infant out of her mother, “but I was a little shaken up afterward.’’

Emergency services arrived moments later. After they cut the umbilical cord, they transported the mother and child to Mount Auburn.

There were no cigars on hand for the father, but each trooper gave him a hearty handshake.

And for the mother, there was a special gift: After she gave birth, Parker asked her whether she wanted to hold her baby.

“She’s beautiful,’’ Parker told her, laying the infant on her chest.

All she could do was smile.

Martine Powers can be reached at mpowers@globe.com.