Frustrated by cruisers racing through downtown every Thursday night, city officials closed the main drag 20 years ago for a weekly farmers market, a move that other towns throughout California also have made.
When Sears, Roebuck & Co. and later JC Penney Co. gave up on the city's core, developers and city leaders brought in trendy boutiques and more popular chain stores -- even a below-ground cinema.
But the latest effort to keep downtown au courant is taxing the patience of merchants and shoppers alike as construction projects make some corners look more like a war zone than a tony town on the Central Coast.
In a downtown core roughly four blocks wide and six blocks long, four major projects have forced pedestrians into plywood-enclosed walkways or made them sidle up to chain-link fencing to avoid cars.
Panicked merchants have posted "Businesses Still Open" signs amid the orange highway cones, cement trucks and construction debris.
Among the undertakings is the city's Century Project, now wrapping up -- a rebuilding of such infrastructure as water and storm pipes throughout downtown.
Adding to the confusion, some building owners are using this state of flux as an opportunity to bring in their own construction crews for long-mandated seismic upgrades.
Downtown grew up around Mission San Luis Obispo, built in 1772, and many buildings are more than 100 years old.
Planners and developers argue that the pot at the end of this reconstruction rainbow will be worth it, allowing downtown merchants to fight off the so-called big-box stores now sitting at, or planned, for the city's borders. (The City Council on Tuesday approved a 140,000-square-foot Costco for the south side of town.)
But try explaining how downtown might be better off in coming years to Vat Poonsopin, the floor manager at Thai Palace. He has seen a drop of 35% to 50% in his lunch trade since one of the largest projects began just across a small street, eliminating more than 100 public parking spaces.
"The lunchtime people only have one hour to eat," he said. "They can't spend half of that looking for parking."
Poonsopin said he still sees young professionals, including county employees, as customers, but senior citizens have dropped completely out of the mix.
"County employees aren't that rich," he said. "They eat out maybe once a week. We love the older people, but they won't walk from there to here."
City leaders admit that parking has always been a bit of a problem downtown, but it hasn't seemed to affect the popularity of the area over time. A healthy tourist industry and wealthy retirees have helped core businesses, along with the boost from Cal Poly San Luis Obispo students and their parents.
The project across from Poonsopin's restaurant is one of those that the city is banking on to keep downtown hip and people coming.
The Copeland family of San Luis Obispo has planned a three-story, 61,000-square-foot retail and office development in the heart of downtown. It will not have attached parking, but the Copelands plan to build a multistory parking garage two blocks away.
The family founded the Copeland's Sporting Goods chain in downtown San Luis Obispo, although it has since sold that franchise.
"Our downtown is very compact and very small," said Shelly Stanwyck, the city's economic development manager.
The Copelands' project "will bring it back to what it was in the 1800s, when it was the commercial core of the entire region of San Luis Obispo County."
But for downtown to be successful and keep its ambience, Stanwyck said, parking should be at the edges of the core business district, instead of next to each shop.
"The big-box stores are power centers," she said. "San Luis Obispo takes more of a specialty lifestyle approach to downtown. It's about a cultural experience for the whole county, about shopping, maybe visiting a museum -- taking your time."
Another large project downtown is the new county administrative building, expected to cost $25 million. It is directly across from the old county administrative center, and the two are expected to accommodate 550 employees.
But the construction has created havoc for area businesses.
Carlos Jimenez has worked for seven years as a busboy at Buona Tavola, an Italian restaurant sandwiched between the Art Deco Fremont Theatre and the county construction site.
Besides being put off by parking problems, Jimenez said, lunch customers are bothered by the noise. Business in that period is down by half or more, he said. "It was supposed to be quiet during lunch," he said, "but they only stop the noise for maybe 30 minutes."
The sheer size of the project right next door still makes people hesitant to use the outdoor patio.
"They had some sort of suspended scaffolding hanging from a crane yesterday, making a lot of noise," said Colin Westerfield, another Buona Tavola employee. "People didn't want to sit under that."
Westerfield and Jimenez are both counting on a better tomorrow, when they are surrounded by white-collar workers brought in from the county's far-flung offices.
Most business managers and owners said they wouldn't consider leaving San Luis Obispo's downtown, even as they lamented the mess.
"As far as we're concerned, we see the same loyal customers every day," said Eric Pettis, manager of the Velvet Foam coffeehouse. "Maybe we have lost tourists who walk in and don't want the hassle, but we can't tell. In the end, it's going to put all these people right here, and they'll all need to drink coffee."