Planning applications relating to schools need to include specific information about transport. This is to assess the impact of changes to the transport demands of school sites. This could be due to more pupils/staff or a change to the access to the school.
Sometimes a school application is for minor change that won't impact on transport. This could be for re-cladding a building for example. In this case, the level of supporting information should be agreed with Highways Development Planning.
The guidance document for school planning applications explains the requirements for transport information.