Why are there restrictions on the sizes of Wheelchairs or Mobility Scooters?

Due to the size and design of our fleet we are only able to carry wheelchairs or mobility scooters that fit within the dimensions set out in 23.4 of the National Rail Conditions of Travel.

In the event of an evacuation or emergency on the train, any wheelchair or mobility scooter outside of the dimensions could restrict the user from alighting and or block emergency exit routes or doorways.