If there is insufficient data for a future transport service to include this in the calculation of the AI at the Design Stage, it should not be accounted for.
If at Post Construction stage the data is available, this can be incorporated.
Whilst certain Design Stage requirements can be based on commitments to achieve a certain performance, this must be based on verifiable data.
16/04/18 Wording amended to clarify that this applies to future services and to allow applicability to UK NC 2018