Colleges are calling for the Government to provide more support for post-16 transport as budget pressures force local authorities to cut funding for student travel.
Further education and sixth form colleges in rural areas are dipping into their own coffers to get students to their campuses. The cash shortage has forced some councils to scrap free transport to college, but others are introducing cut-price travel for students.
Nigel Robbins, principal of Cirencester College in Gloucestershire, described national support for student transport as a "hotch potch".
His college pays more than pound;200,000 a year to support bus services for students in an area which lacks public transport. Half of the cost is paid by parents.
"You won't find many schools in the situation where they have to spend their own money enabling students to get into their own sixth form," he said.
"It doesn't happen because the policies are normally sufficiently supportive, but in our case we're having to make very heavy subsidies."
Principals debated the issue at this week's Association of Colleges and Sixth Form Colleges' Forum 16-19 summer conference.
Information about post-16 transport and its cost to colleges across the country is patchy, and policies vary hugely. Some North Wales councils, for example, have piloted half-price bus fares for young people up to 18.
In contrast, Lincolnshire County Council has axed free transport for FE and sixth-form students. From September they will be charged pound;180 a year.
The policy has had knock-on effects beyond county boundaries. John Leggott sixth-form college, in neighbouring North Lincolnshire, takes students from Lincolnshire, some of whom travel up to 16 miles. The college has decided to subsidise over half the cost of their transport. Principal David Linnell says if it didn't it could lose around 40 students.
He said students receiving their weekly education maintenance allowance would have particular difficulty paying the pound;60-a-term up-front charge. "There's a cash-flow problem for particular families, who by their very nature will have difficulties because of their level of income," he said. The AoC says students should have equal access to learning across the country. It is lobbying for a nationwide strategy on transport to guarantee this.
It says the education and inspections Bill currently going through parliament is unclear on the future roles of local education authorities and the Learning and Skills Council in post-16 transport.
Julian Gravatt, AoC director of funding and development, said: "It is always disappointing to see councils reducing subsidies for student transport as cutbacks herald a restriction in choice for students and impact directly on their opportunities. We will continue to push for a nationwide strategy on student travel that ensures equality of access to learning across the country."