It’s strange what you remember about the ho-hum moments before your life is upturned. For Nancy Harrison-Noonan, it’s the blueberries.

She’d just gone shopping at the Safeway on Church Street and carried a basket of blueberries in a tote bag flung over her shoulder. She was walking home south on Guerrero Street and crossed 18th Street on a green light.

For the driver who was heading north on Guerrero and turning left onto 18th Street, that last memory is spotting a different person across the intersection in a lion costume. His friend remarked on the odd sight, and the driver turned to look at just the wrong moment. He didn’t see the woman in the crosswalk, but she sure saw him.

“He was coming towards me, and I was thinking he was going to stop, and then I thought, ‘He’s not going to stop!’” Harrison-Noonan, 67, remembers of that Saturday morning, Feb. 16. “It felt like the seconds just expanded. I don’t remember anything until I came to, and a woman was yelling, ‘Don’t move your head! Don’t move your head!’”

She was lying on the pavement next to her smashed blueberries.

Harrison-Noonan became a member of an unfortunate and growing club that morning: those injured in traffic on the dangerous streets of San Francisco. Every 15 hours on average, someone is taken to San Francisco General Hospital after being hit.

We hear about pedestrians and bicyclists killed in traffic, their stories making the news and lamented on social media. But we rarely hear about those who sustain major injuries. If we did, there would be more than 11 stories about them every week — and perhaps more urgency to fix our deadly streets.

“Severe crashes don’t make the headlines even though they can absolutely devastate lives,” said Jodie Medeiros, executive director of Walk SF, a pedestrian advocacy group. “As a result, most people don’t fully realize the scale of the public health crisis that we’re in.”

Like fatalities, injuries are rising. In 2014, the city set its Vision Zero goal of ending traffic fatalities by 2024. Halfway through that 10-year span, 26 people have died in traffic this year, down from 31 in 2014, but up from 20 in 2017.

In 2014, 471 people were severely injured in city traffic, 106 of them critically, meaning their life was in jeopardy. Last year, that number rose to 592 people with severe injuries. Of those, 130 sustained critical injuries.

They all survived, but some were left with lifelong physical effects, including traumatic brain injury.

By comparison, Harrison-Noonan was lucky. An ambulance took her to S.F. General Hospital, where her daughter met her and joked that the blueberries had taken some of the impact and saved her. She was kept at the hospital for several hours, undergoing a barrage of tests.

She was worried. She’d moved from Wisconsin the year before to live near her daughter and son and didn’t want to burden them.

“I thought, ‘Oh no, I’m going to be a paraplegic,’” she recalled. “I would have rather died than be severely injured.”

Fortunately, her injuries were relatively minor. She had a bloodied bump on her forehead, a sore hip and side and black eyes. She had vertigo and felt dizzy for months whenever she stood up.

She was released from the hospital the same day, but had a lot of questions. She’d been knocked unconscious and wanted to understand what had happened. Who had hit her? What had happened to him?

She went to the Mission Police Station a few days later and asked to speak to the officers who’d arrived at the scene. But the man at the desk said none of them was in, and she felt like he gave her the brush-off despite her tears and two black eyes.

“I said, ‘I’m having trouble dealing with this. I just want to know what happened,’” she recalled. “If you can’t be responsive to me, who are you responsive to? I’m an old lady!”

Five days after the injury, she emailed the police, asking for the report of the incident. She had to ask again a week later after still not receiving it. She finally received it on March 13, nearly a month after the collision.

It included the name and phone number of the person who hit her. Maybe she could finally get some answers — from him.

There are many reasons for Vision Zero failing to make an impact, as laid out in a Department of Public Health presentation to the Vision Zero Task Force in September.

The economic boom has created more jobs, drawing more people to our already crowded streets each day. There were 630,000 more miles traveled daily by vehicles in San Francisco in 2016 than there were in 2010. Ride-hailing companies such as Uber and Lyft accounted for 47% of the increase.

The city’s aging population means 1 in 5 residents is a senior and therefore more vulnerable to severe injuries. The city’s spike in homelessness also put more people on the streets, some of them mentally ill and more susceptible to being hit, according to the presentation.

But the city is not responding as quickly or effectively as it should. Even making the smallest improvements — like adding stop signs or traffic lights or crosswalks — can take years of pleading by neighbors, if they happen at all.

Bigger changes like regulating ride-hailing companies, implementing congestion pricing, lowering speed limits, or installing automated speed enforcement systems have been discussed for years. But in the timeworn tradition of City Hall, they’ve mostly gone nowhere.

Harrison-Noonan had questions about the collision, and it turns out the man who hit her did too. His name is Hayden, and he’s 24. Like the woman he’d hit, he’d just moved to San Francisco from the Midwest, relocating for a job in finance.

Hayden spoke to me on the condition his last name not be used. The Chronicle generally doesn’t identify people who are not charged with crimes, and he wasn’t.

Hayden said he had been driving a couple of friends to get brunch when he got distracted by the person in the funny lion suit and struck Harrison-Noonan. He said he stopped, remained at the scene and spent 45 minutes talking to three police officers.

They let him leave without even issuing a ticket.

I was surprised by that. Was he?

“Yes and no,” he said. “I don’t think I was being reckless. I had no mal intent.”

This is despite his exact action — failure to yield while turning — being recognized by the city as one of the five most dangerous driving behaviors when it comes to hitting pedestrians. As part of Vision Zero, the Police Department is supposed to ensure at least half the tickets it issues are for those five behaviors.

But statistics obtained by The Chronicle in August showed the overall number of traffic tickets issued by police has dropped precipitously since 2014, the year Vision Zero was created, and tickets for those five behaviors have gone down too.

Medeiros said police need to step up enforcement to curb what she calls “traffic violence.”

“These are not accidents. These are crashes,” she said. “These are conscious behaviors, and they have repercussions on people’s lives, and that has to be taken seriously.”

Hayden said he did take the collision seriously. He said police wouldn’t give him any information about the woman he hit.

“It was this big question mark,” he said. “For the next month, I wasn’t sure if I killed her.”

He was about to find out. He got a text from the woman he’d last seen being loaded into an ambulance.

David Stevenson, a spokesman for the San Francisco Police Department, acknowledged Hayden should have received a ticket.

“Upon review of the report, it would appear a citation should have been issued,” he wrote in an e-mail. “Our officers are trained to cite at the scene of a collision when it can be determined that a violation occurred. The officer will undergo retraining to address this.”

Several officers were at the scene, so it seems they should all undergo the retraining.

Cmdr. Daniel Perea, who oversees the traffic division, said traffic tickets are down from previous years, in part because it’s so much more complicated to issue one.

“We are tracking so much data regarding the stops that we conduct, who is stopped and what occurs at that stop,” he said. “At one time, we were entering information in less than 20 fields. Now we’re entering data in excess of 40 fields.”

A lot of that stems from a state law passed in 2015 designed to stop racial profiling by police. It requires that police fill out a host of information about each stop including guessing the person’s race or ethnicity, gender and age.

“The work of issuing a citation takes longer,” Perea said.

Stopping people because they’re black or brown is horrendous. But looking the other way at bad behavior isn’t the answer either. And notably, Hayden, the man police let off the hook after sending a woman to the hospital, is blond, blue-eyed and white.

Harrison-Noonan and Hayden texted off and on, and it didn’t make Harrison-Noonan feel much better. She learned Hayden didn’t even have car insurance — he said he mistakenly thought he was still on his parents’ policy — though her Medicare policy paid the hospital charges.

She was also angry that he hadn’t received a ticket.

“How can you hit a person with five or six police officers there, lie about your insurance and come out with no consequences?” she asked. “He didn’t even get a stern talking-to.”

Harrison-Noonan thought she’d feel better if they met in person, and Hayden agreed to join her the evening of Oct. 1 at a coffee shop in the Mission.

He told her what he remembered from that Saturday morning. She told him about the dangers of walking in San Francisco, but wasn’t sure he really got it. And she was irked he didn’t even offer to buy her a coffee or muffin. They parted ways after 20 minutes.

They’ve reached a sort of detente, though. Shortly after they met, Hayden left chocolate on her stoop with a note saying he would volunteer with Walk SF.

He also wrote her a $1,400 check and said another of the same amount will be delivered next month. It’s to help her cover her Medicare Part B monthly payments, yoga classes to ease some lasting soreness and anxiety, and monthly Clipper cards because she’s more reliant on Muni now that she’s unsure of walking city streets.

“I’m feeling better about him,” she texted me the other day.

She doesn’t feel better about walking around the city, though. She works to craft safer routes when running errands, affixes light-up straps to her wrists and backpack when walking, and waves her arms around when crossing the street in an attempt to be more visible to drivers.

Hayden, too, hasn’t been able to shake it.

“Every time I get into the car, it is that fear,” he said. “No matter what, it slips across my mind like, ‘Oh shoot, pay attention, don’t mess up.’ Because in the blink of an eye, you can make a really big mistake.”

It’s a lesson for everyone who navigates San Francisco’s dicey streets. Pay attention. Don’t mess up. Another person’s life could hang in the balance.

San Francisco Chronicle columnist Heather Knight appears Sundays and Tuesdays. Email: hknight@sfchronicle.com Twitter: @hknightsf Instagram: @heatherknightsf