For most folks, sidewalk cracks and bumps are minor obstacles so easily overcome that they'd never even consider calling City Hall to report the problem.
But for Phillip Grazide, uneven sidewalks are a minefield, painfully jolting his wheelchair-bound body whenever he rolls over them on his motorized scooter.
"My goodness gracious, some of these sidewalks are terrible!" says the retired prison guard. "They're war zones!"
So Grazide, whose arthritis has largely confined him to a chair for 12 years, has taken up arms in the fight.
With a can of fluorescent orange spray-paint in one gnarled hand and a cellphone in the other, Grazide, 73, is on a mission make the city's sidewalks safer.
"I'm trying to save lives," he says.
To alert city public works crews and pedestrians to what he sees as hazardous sidewalk conditions throughout the city, Grazide has taken it upon himself to highlight with bright paint the wide cracks, dangerous dips, and sidewalk sections thrust upward by unruly tree roots.
Whether it's grocery shopping for him and his 95-year-old mother or taking the bus to chat up the ladies at the Bennett Valley Senior Center, Grazide is packing a can of bright spray-paint wherever he goes. From the saddle of his trusty maroon Quicki Freestyle scooter, Grazide is quick to draw on any trouble he spots.
He then calls the city's sidewalk hotline and harasses them to fix it. City public works crews usually respond quickly and get the problem resolved, he said.
"Those guys do a great job once they know it's there," Grazide says. "I'm just bird-dogging them."
The city puts a high priority on quickly repairing what they call "sidewalk uplifts," most of which are caused by tree roots, said Steve Schiavone, the city's street maintenance superintendent.
A three-man crew is dedicated to the task, usually building asphalt patches meant to be temporary fixes. But this year there has been a 60-percent increase in complaints, from 220 by this time last year to 350 so far this year, Schiavone said.
There's always a surge in complaints in summer, when more people are out walking, but Schiavone isn't sure why they've spiked this year.
"We're seeing work request for these uplifted sidewalks generally every day," Schiavone said.
Recently, when the complaints got to be too much, the department put a second crew on the job to help clear out the backlog, Schiavone said.
"It's difficult for us. We don't have extra personnel," he said, noting there are 500 miles of roadway in the city, much of it with sidewalks on both sides.
Handicapped people aren't the only ones challenged by the city's choppy sidewalks.
Rincon Valley resident Ben Stanley was walking in the 1300 block of Beaver Street last month when he took a fall he won't soon forget.
The 69-year-old retired entrepreneur had just purchased a set of hanging baskets from a yard sale and was carrying them back to his car when he stepped in a depression in the sidewalk.
He twisted his ankle, lost his balance, stumbled off the curb and did a faceplant in the middle of the street, breaking his nose, mashing his teeth, and scraping his forehead, chin and knee, he said.
"When I hit the pavement, I felt a crunch!" Stanley said.