Roy Santos would love to live anywhere that’s more stable and comfortable than his cramped trailer on Bayshore Boulevard.

Every time he showers or uses the bathroom, he has to collect all of his wastewater and figure out where to legally dump it. He constantly has to worry about break-ins, parking tickets or unwelcome neighbors. But he doesn’t know where else to go.

“It’s brutal,” said Santos, a veteran, who has been homeless for about six years after falling on “hard times.”

More than 1,700 people like Santos live out of their vehicles in San Francisco, and that population spiked 45% over the last two years. In response, city officials cleared a parking lot near the Balboa Park BART Station where they will allow up to 30 vehicles to park for 90 days beginning this week or early next.

The lot is being dubbed a “Vehicle Triage Center,” where people will have daily access to case managers, portable toilets and a portable shower three times a week. While city officials hail it as a productive first step toward addressing vehicular homelessness, others see it as an inadequate response to the crisis and a veiled attempt to clear RVs from residential neighborhoods.

“Thirty parking spots for all of these RVs?” scoffed Stephanie Brown, 50, as she sat on the couch inside her trailer, which was parked down the street from Santos and a few miles away from the proposed site. “You’ve got to be high.”

San Francisco’s overall homeless population has grown 17% in the past two years, much of that attributed to people using their vehicles for shelter. Vehicular homelessness has become prevalent all over the West Coast, and other cities, like Oakland, have opened up similar lots to address the issue.

Brown likes the idea of parking somewhere she wouldn’t be bothered — especially after someone broke into her trailer recently and stole her clothes and speakers. But she is skeptical of how much the city will actually help her. Brown’s friend Corey Pounders, who was hanging out with her Tuesday morning, said he spent several months in a Navigation Center — a shelter with extra resources to help connect people with housing — only to wind up back in his van.

“They didn’t do s—,” he said. Brown and Pounders said they would be open to the idea of moving into the lot, but no one has offered them a spot yet. The Department of Homelessness and Supportive Housing is first offering spots to people who are parked near the site, and then will eventually move to other neighborhoods.

San Francisco — overwhelmed by its homeless crisis — lacks enough affordable housing, Navigation Center beds and drug treatment programs. Mayor London Breed is working to create an additional 1,000 shelter beds by the end of next year.

The Vehicle Triage Center is a pilot program and will be dismantled in the fall, when work begins on turning the lot into an affordable housing development. Since the center is only temporary, the city was careful about costs. Instead of installing plumbing or electricity, the center has Porta Potties, a mobile shower three times a week and solar panels.

The city spent about $500,000 on one-time capital costs and plans to spend about $1 million on operating costs, according to the department.

The city’s Vehicle Encampment Resolution Team has been working since October to identify people who would be a good fit for the site. The Department of Homelessness says it is focusing on people who are the “highest needs,” and who want to eventually move into more permanent housing.

The department says it has identified 26 vehicles that could move into the space either this week or next, but a spokeswoman said that number could shift in the coming days if people change their mind about the site or find a more permanent option.

Urban Alchemy, a nonprofit, will manage the site with 24/7 security. There will also be case managers to provide referrals to shelters, addiction treatment and mental health care — if the resources are available elsewhere in the city.

“This is a start. I don’t think this is the solution,” said Lena Miller, CEO of Urban Alchemy. “We’re throwing everything at the wall to see what sticks.”

Supervisor Ahsha Safaí, whose district includes the lot, sponsored the legislation to create the lot with outgoing Supervisor Vallie Brown. Once the site is up and running, he plans to work with the San Francisco Municipal Transportation Agency to eventually prohibit RVs from taking up residential parking spots in certain neighborhoods.

While the lot is in an area with one of the smallest homeless populations in the city, Safaí said vehicle campers have become increasingly common in his district, which includes neighborhoods like the Excelsior and Mission Terrace. These vehicles have popped up all around the city and are most prevalent in more sparsely populated areas, like the Bayview, where Santos and Brown were parked Tuesday morning along with several other vehicles.

“This is a learning experience,” Safaí said, as he stood in the parking lot Monday morning. “Our intention is to ensure that we’re expanding this to other locations.”

Few neighbors opposed the triage center, unlike the Embarcadero Navigation Center, which was tangled for months in a lawsuit filed by nearby residents. But some residents were still skeptical of the idea.

“I don’t like it,” said Fernando Cruz, 51, who lives a few blocks away from the site. “We want the neighborhood to stay peaceful.”

But Glenda Hope, who lives a block away from the site and was on the advisory committee for the program, said, “It’s a good thing, but it’s also a very tragic thing that we need this.”

“I hope for the day that we don’t need it,” she added.

Trisha Thadani is a San Francisco Chronicle staff writer. Email: tthadani@sfchronicle.com Twitter: @TrishaThadani