Pupils in Warwickshire are travelling to school without chaperones on some coach services as the new academic year starts.
The county council, which must save £33m by 2014, decided to remove some passenger teaching assistants in April as part of budget cuts.
The chaperones make sure children behave and wear seatbelts.
Parents said they provided an essential service but the council said only four services had been affected.
From September, services in Wolvey, Cubbington, Newton Regis and Long Lawford have changed.
'Driver distracted'Councillor Heather Timms said the service would remain in place where suitable.
She said: "If there's mixed age groups of children, if the pick up and drop off points for the school is not suitable for children to go from the bus to the school, then we will be providing passenger assistance and also, if there is a risk of behavioural problems going on, then we will obviously look at those."
Annabel Shackleton, who has a five-year-old son, said the coach drivers could be distracted.
She said: "If there is any rivalry between any of the older children on the bus that is going to be so distracting for the driver and that's something the chaperons used to do.
"It's sort of the role, not only to ensure that children are safe and secure but actually ensure there's not any rowdiness so the driver can concentrate on what they have to do."
The council said service would be assessed individually and it was difficult to say how much money was likely to be saved.