The city's planning commission is considering the environmental impact of the 555-bed hospital that's planned for the corner of Van Ness Avenue and Geary Street.
Nurses and community groups say the new California Pacific Medical Center facility would create traffic nightmares.
"We're citing a hospital on a very congested roadway where emergency times may be more than they otherwise had been at a better site," California Nurses Association spokesperson Matt Vespa said.
"It's a transit rich corner; we feel that it is a good opportunity to rebuild our hospitals without disrupting care on any of our campuses," CPMC Vice President Judy Li said.
If the planning commission OKs the environmental impact report, the proposal would then move to the Board of Supervisors for final approval.