SAN JOSE — After decades of downtown development, San Jose has arrived at a crossroads in its quest to create a truly great downtown, according to a report released Tuesday.

The report, prepared by SPUR, a nonprofit group consisting primarily of Bay Area business and government leaders, recommends that city officials insist on high-density office, retail and residential projects near future BART stations and transit hubs, make the downtown more pedestrian-oriented and promote the concept of a central San Jose that has the downtown district as its core. All of these tactics are aimed at one critical result: Getting more people in a still-sparsely populated urban core.

“The city will squander an opportunity if it doesn’t maximize its potential,” said Jessica Zenk, co-chair of the report and senior director for transportation policy for the Silicon Valley Leadership Group. “Failure won’t mean the demise of the downtown, but it will be the difference between a good downtown and a great downtown.”

San Jose seeks to reshape its downtown at a time when downtown districts are back in vogue, with more residents and companies receptive to denser, more urban locations. But it’s not enough for San Jose to have good timing on its side, according to the report, titled “The Future of Downtown San Jose.”

“Downtown needs more people,” the report said. “It is neither small enough to navigate easily nor large enough to draw significant crowds on a regular basis. As a result, it’s not attracting the level of activity necessary to succeed.”

Jobs are one key measure of San Jose’s need for downtown development, according to the report. Downtown San Jose has about 39,000 jobs, compared to 83,000 jobs in downtown Oakland and 317,000 jobs in downtown San Francisco, according to a U.S. Census Bureau report cited by SPUR.

A major factor behind the disparity is that both downtown San Francisco and downtown Oakland emerged as the principal job hubs for those cities while the primary employment hub for San Jose is the city’s north side.

“A lot of businesses left downtown San Jose in the 1970s and 1980s, and a lot of those jobs went to suburban campuses,” said Garrett Herbert, a co-chair of the report and a managing director in the San Jose office of Deloitte, a large consulting firm.

San Jose overall has the potential to add 400,000 jobs over the next 30 years, and the downtown alone could add about 49,000 jobs over the same period, according to San Jose officials and the SPUR report. The city also notes that about 90 high-tech companies are located in downtown San Jose.

City officials agree that they have key development decisions to make, especially since BART has agreed to extend train service to two new downtown San Jose stations, one at Diridon Station and the other one near Santa Clara and Second streets, though no dates for completion have been set and there currently is not enough money to extend the BART line past its current planned terminus in the city’s Berryessa district.

Kim Walesh, San Jose’s economic development director, said the city “highly values” the new report and already has taken initial steps to fulfill all of its major recommendations.

“San Jose is at the crossroads,” Walesh said. “We can transform this good downtown into a great downtown.”

The report also suggested that city planners create more urban walkways such as Paseo de San Antonio and Fountain Alley to encourage people to stroll around the downtown. And it called for more street fairs, live music, festivals and other crowd-attracting events.

“When people in the South Bay think of going to an urban environment, we want them to go to downtown San Jose,” said Egon Terplan, the report’s author.

Contact George Avalos at 408-859-5167. Follow at Twitter.com/georgeavalos.