But the council says an average of only one person per trip uses the service and the new on-demand scheme would be better for passengers.
The changes will affect bus routes 80 and 81 which will be replaced with an on-demand service and current passengers will be able to use an app or phone to catch a bus from July next year.
Pamela Harley has used the bus loop at least twice a week for the past six years to attend doctor’s appointments and get to the supermarket.
"They've got no regard to the people that do use it and rely on it, " Ms Harley said.
The current service is run by a single bus that operated a fixed route every 40 minutes.
The 68-year-old pensioner dealt with "aches and pains" and a trip to the supermarket and back was about 1.3km for her and her neighbours, Ms Harley said.
"For an older lady or an older gentleman trying to get up the street with a wheelie walker, it's not going to work."
An app was available to allow bus-users to track the buses and how far away they were from the bus stop, but she believed she might be the only person who knew about it.
"I only go there when I know it's nearly here, but a lot of other people don't know that."
The nearby bus stop had no seating and caused issues because many elderly residents were unable to stand for long periods of time, she said.
"Considering that Mosgiel has one of the largest communities of older people [and] a lot of them have cars and they're not going to be able to drive their cars forever and they'll be relying on that bus to get around."
Her preferred solution would be not to change the bus routes.
Otago Regional Council transport manager Lorraine Cheyne said the current service had an average of roughly one passenger per trip.
"The service is highly valued locally, but not well patronised.
"The new service will provide greater coverage and flexibility than the existing services."
The change was being made due to the success of on-demand services throughout New Zealand, Ms Cheyne said.
"Council’s long-term plan consultation process showed interest in widening the area of public transport coverage in Mosgiel.
"Compared to the existing fixed routes, this will deliver a focus on accessibility with flexible routes and flexible pick-up/drop-off locations."
