The Port Authority of New York and New Jersey approved $70 million to begin planning for a new bus terminal on Manhattan’s west side, turning aside requests by some New York officials to study alternatives.

The bi-state agency Thursday also adopted a 10-year capital plan, which allocates $3.5 billion to replace the decrepit bus terminal. Port Authority officials have estimated the terminal could cost as much as $10 billion and more than a decade complete.

“Meeting the needs of the growing number of the region’s bus commuters is an essential component of the Port Authority’s transportation mission, and this project will be done while fully respecting and minimizing the impacts on Manhattan’s West Side,” said Port Authority Executive Director Pat Foye in a news release.

The neglected depot was opened in 1950 and expanded in 1979. It serves about 230,000 passengers daily and is operating beyond capacity. The Port Authority expects users to increase 45 percent within 23 years.

Planners will assess the best location for the terminal, consulting with elected officials in both states, neighborhood residents and previous planning studies, the Port Authority said. The effort will also identify potential bus staging areas and seek to address an acute parking shortage that leaves buses idling on Manhattan streets before picking up afternoon commuters.