Comment
Draft Local Plan
Representation ID: 15877
Received: 11/05/2016
Respondent: National Highways
Additional isues. Consequences of the adopted process.
As discussed earlier in this note, no assessment is made of M25 junctions. The increase in the number of trips at M25 Junctions 28 and 29 is higher than at any of the junctions modelled. AECOM recommend that capcity tests are undertaken to determine the resultant operation performance at these junctions. This type of assessment could have used a full highway assignment model had one been available. The assignment from such a model would differ in several important ways:
The extent of increasing junction delays would affect route choice. (This has two consequences: Several routes will be used by development trips between zone pairs; and existing trips may change route as a result of congestion caused by development trips).
Increasing congestion may result in interference (blocking back) between junctions.
See attached