Poor behaviour on school buses in Wales continues to put young lives at risk, according to new research. In one incident a seat was thrown from an upstairs bus window on to a car, and in another a girl's hair was set on fire.
The findings come as council estimates suggest the total bill for overhauling school transport in Wales could run to an extra pound;20 million a year.
The Welsh Local Government Association (WLGA), which commissioned the research, said there was a huge commitment to making improvements but that substantial investment by the Assembly government was vital.
The Assembly's education committee has made a series of recommendations to improve safety on school buses, following the death of 12-year-old Stuart Cunningham-Jones in December 2002. These include installing CCTV cameras, employing escorts, phasing out the use of double-decker buses, staggering school runs, and training drivers.
The WLGA research, to be published next month, found innovations such as playing pop music and CCTV were all helping to curb bad behaviour. One driver said pupils on his run had gone from "devils to little angels" after cameras were installed. But overcrowding and old buses were still a concern, with many pupils refusing to use seatbelts provided.
Stuart died at Ystradowen, near Cowbridge, Vale of Glamorgan, while a bus passenger. An inquest jury concluded the driver lost control after unruly pupils grabbed the wheel.
His father David Cunningham-Jones, a founder of Stuart's Campaign to improve school transport safety, said: "A price cannot be put on a young life."
Researchers looked at eight Welsh local authorities and interviewed schools, pupils and drivers. They found pupil behaviour on school transport was "mixed", with many journeys "largely trouble-free".
Most of the worst examples involved secondary pupils on top decks. One driver described his run as "20 to 30 minutes of torture", while a pupil claimed the buses on his service were "more ancient than his dad".
Operators said they were finding it hard to employ drivers and escorts willing to put up with bad behaviour. But drivers were also said to set a bad example, with reports of some using mobile phones while driving.
A quarter of schools were concerned about the poor quality of the school buses. And some heads remain unsure of their legal obligations concerning transport outside the school gates.
Anna Brychan, director of the National Association of Head Teachers Cymru, called for the responsibilities of the various agencies to be made crystal clear.
Meanwhile, in Caerphilly, a recent council policy paper estimated that bringing its school transport services in line with the education committee's recommendations would cost around pound;900,000 extra every year. It already plans to extend CCTV to all secondary runs at a cost of pound;45,000.
If other councils were to follow, the total bill for Wales could be as high as pound;20m a year. Caerphilly said concerns had been heightened by the death of 12-year-old Jasmine Allen, a pupil at Newbridge comprehensive.
She died, and 30 other pupils were injured, when their minibus collided with a car in May. Meanwhile, local authorities are waiting for Assembly government guidance on improving school transport, expected in November.
A government spokesperson said: "We expect LEAs to make best use of existing resources to provide reliable, safe school transport which meets local needs.
"Many school transport improvements have been achieved by LEAs already, at little or no additional cost, such as use of codes of conduct to improve pupil behaviour on buses and CCTV on problem routes.