Palo Alto's glacial journey toward its most urgent priority -- a new police headquarters -- may finally reach its terminus in a nondescript parking lot on Sherman Avenue.

The lot, which sits next to the Santa Clara County Superior Court and just south of California Avenue, emerged on Wednesday as the most promising candidate for the $47-million project that tops the city's list of infrastructure priorities.

Once complete, the new public-safety building will allow the police department to ditch its cramped and seismically unsafe headquarters at City Hall and share the new facility with the emergency dispatch center, Palo Alto Fire Department's administration, the Emergency Operations Center and the recently established Office of Emergency Services.

The idea of replacing the existing police building first surfaced about 30 years ago and the effort has proceeded in fits and starts ever since. On Wednesday, the City Council signaled its desire to finally see a breakthrough when members informally endorsed the option of building the new facility at 250 Sherman Ave.

Under a plan proposed by City Manager James Keene and Public Works officials, the new building would be constructed next to another new facility -- a parking garage built to compensate for lost public parking and address the existing parking shortage in the California Avenue Business District.

The Sherman Avenue lot has its challenges, however. At only 1.2 acres -- which could be expanded to 1.5 acres by eliminating a right-of-way on Sherman -- it would still be a tight fit for the 44,848-square-foot building.

The Sherman lot was one of three options the council considered, and the council's enthusiasm for the site was in many ways a reflection of how unpopular the other options were. Both of the other two proposals would have placed the new public-safety building near the Baylands, in tidal flood zones and far away from the city's center.

One considered the Los Altos Treatment Plant site on San Antonio Road, while the other looked at the PG&E substation at 3120 West Bayshore, an option that would have required the utility company to go through the four-year process of moving its equipment from the site.

As Mayor Karen Holman put it: "I kind of feel like we're being presented three options, two of which aren't options."

Most council members agreed. Councilman Marc Berman was the first to endorse the Sherman option and his colleagues quickly followed suit.

"None of them are perfect, but of those that aren't perfect, Sherman Avenue is by far the best," Berman said.

Councilman Greg Scharff, who often talks about the need to build a new parking garage on California Avenue, was more excited. He particularly liked staff's suggestion that the new garage could include ground-floor retail that would be designated as below-market-rate for the preservation of local shops.

"I'd advocate for moving full speed ahead on the Sherman Avenue site," Scharff said. "I don't see any other opportunities out there."

City staff considered and discarded more than 20 other locations in recent months. In many cases, the sites were not for sale. In some, the site proved too small or the price was too high.

Despite its small size, the Sherman site has one advantage over other options: it is located near the city's geographical center and next to the city's eclectic "second downtown." Its high visibility is one reason why Keene said he supports it over the other two options on the table.

"Even though it's acknowledged that they all have challenges, the Sherman Avenue site in my view has more upside to it and less downside than the other two," Keene said.

One of the values of the site, he said, is its high community visibility, which is important both for access and for symbolism.

"Currently, in contemporary conversations we're having in our society about police and community relations, it's important that we're sensitive to that," Keene said.

Councilman Cory Wolbach agreed, saying the Sherman Avenue is "at the top of the list for very good reasons."

Councilman Tom DuBois was more cautious and warned that solving California Avenue's parking problem and compensating the area for the lost parking lot could require a "monster garage." Even so, he also signaled his measured support for the Sherman Avenue site.

"None of the sites seem great, but it seems like we're coming to consensus on Sherman Avenue," DuBois said,

The Wednesday conversation was strikingly different from prior discussions of the public-safety building for two reasons. Unlike in the past, the city now has $57 million allocated for the project under an infrastructure plan the council approved in June 2014.

Also, the new proposals don't depend on private developers or land that the city doesn't own. The city's last proposal for a police building died in December 2013, when developer Jay Paul dropped a plan to build an office complex at 395 Page Mill Road, a project that included a police building as a public benefit.

Before that, the city had entered into an option to buy two properties on Park Boulevard for the new facility. That agreement was dropped in 2009, when the city's coffers dried up in the economic downturn.

Now, the city has the land, the money and a council eager to get working on the project. Even so, some hurdles remain. The new proposal would require extensive design work and environmental analyses before construction would begin.

Councilman Pat Burt also pointed to the circulation problems that would result from removal of the Sherman Avenue right-of-way and directed staff to study this issue further.

Yet the council, by and large, agreed with Berman's request not to "let the perfect be the enemy of the very good."

Before joining the council, Berman had served on a citizen committee that surveyed the city's infrastructure needs and that described the existing police headquarters as "unsafe and vulnerable" in its final report.

"It's time we come to a decision on the site and mitigate whatever issues might exist and start moving forward so that we can develop the public-safety building for Palo Alto for the next 50 years," Berman said.