http://www.durham.gov.uk/concessionaryspareseats
Here's details of the schools in Durham and the various systems in place, including schools who don't have an agreement with the council, details of free school travel and £1.50 a day travel.
There is a methodology/reasoning behind it, but unsure what that is at the moment.
RE: Go North East: Latest News & Discussion - August 2016
'Illegitimis non carborundum'