The Friends of Gordon Falls are hoping the National Parks and Wildlife Service will rethink the design of changes planned for the lookout.
Residents at the quiet reserve were alarmed when they were letter-boxed by NPWS in April with details of a proposal to build a new elevated walkway and viewing platform overlooking the Jamison Valley, with construction to begin this month.
They were concerned that the new facilities would attract large tourist coaches, which are unsuitable for the small surrounding streets, as well as increase demand on toilet and other facilities, which are inadequate for large numbers.
NPWS held an on-site information day last Saturday to outline the plans to make the lookout more accessible for families, seniors and people with mobility issues.
The Friends of Gordon Falls said the use of the area by those groups had markedly increased over the last decade so the decision to expand and encourage them to visit was commendable.
But the group feared the design would likely attract mass tourists on coaches rather than help people with mobility difficulties.
Friends convenor, Annie Fraser, said: "We congratulate NPWS on this initiative but we ask that the project be halted to allow for the design to be reviewed. It is the design that is the worry.
"If we could stop and take a look at how the park is currently used, get the council on board and get someone from the mobility-challenged community to have some input into the process, we could come up with a park for a diverse section of the community that proudly provides facilities and enhanced opportunities."
Ward 1 councillor Kerry Brown proposed that the planned 60-metre square viewing platform be halved in size.
"National Parks say the upgrade is about wheelchair accessibility but there is no denying that the sweeping walkways and large viewing platform will be a drawcard for big coaches wanting a 20-minute toilet and photo op stop.
"My advice is that the new viewing platform should not be big enough to fit a coach load of people all at once. At half the size the platform would still be wheelchair accessible without being coach-bait."
According to Cr Brown, council has now requested that NPWS set up a project control group with council staff and urged that community members be included.
The Gordon Falls upgrade is part of the state government's upgrade to the cliff top walk between Wentworth Falls and Katoomba.