The Beverly Hills City Council on Monday gave final approval to a proposed $500 million revitalization project for the Beverly Hilton Hotel that would include the first Waldorf-Astoria Hotel on the West Coast.

The long-expected approval came in the form of a zone change that allows construction of the 9-acre site at the intersection of Wilshire and Santa Monica boulevards.

However, the project by Oasis West Realty LLC could face another hurdle: Late last week, neighboring residents because of traffic concerns announced they intended to gather signatures to send the previously approved general plan amendment before Beverly Hills voters in November. About 2,200 signatures are required and referendum organizers said they expected to exceed that target.

Besides the proposed Waldorf-Astoria Hotel, the project calls for two luxury condominium buildings with a total of 100 units, a conference center and public gardens. Parking would be moved from the existing above-ground structure to an underground structure.

Beverly Hills officials say the project would generate $729 million in tax revenues over 30 years, in addition to an up-front $10 million cash contribution to help mitigate some of the project’s impacts.