The city council pays for school buses or taxis for those eligible through disability or distance from school.
It is proposing some children with disabilities could be trained to use public transport instead, to save about £420,000.
Legal advice is being sought to assess whether the idea complies with legislation.
Earlier this week, Coventry City Council outlined more than £15m of savings, saying its government grant had been reduced from £214m in 2010 to £135m for 2015.
The councillor for education, David Kershaw, said taxi services were "very expensive".
He said the eligibility of all school age children would be re-assessed and those 16 and older would have "to make their own way [to school or college] because at that point the money runs out".
"Let's try and help those young people be trained, be supported, so they can use public transport in preparation for their adult life," he said.
The proposal, which would come in effect next September, would affect about 270 children with special needs or disabilities, but not those with disabilities too severe for training to be appropriate, he added.
One of those is Jack McGovern, 7, who has autism. His mother said: "At the moment I can't see that he'd be able to get a bus by himself.
"I'm not confident at all about this change or about other changes they might want to bring in the future."
Jane McConnell, chief executive of the Independent Parental Special Education Advice charity, said the proposal needed to be checked against legislation.
By law local authorities have to provide assisted transport for children with special educational needs and disabilities.
Ms McConnell said: "We're talking about children with complex needs who often don't go to the closest school and may have to travel a long way to go to a school that suits their needs."
She said other local authorities had abandoned similar proposals after legal research and consultation.
The council's consultation and an online survey will run until 23 January.
Children with disabilities or special needs in Coventry could have their school transport cut.