David Simmonds Consultancy Limited

Greengauge 21

DSC's contribution to the Greengauge 21 study of a possible high-speed rail network for Britain was focussed on the regional economic impacts of the proposals.  The work was carried out as part of the wider study conducted by SYSTRA and MVA Consultancy.  The regional economic modelling involved a full application of the DELTA package, though this was not a full land-use/transport model - it took costs of travel from the transport model, but the possible link from regional economic changes back to travel demands was not implemented.  Unusual features of the model were that

  • rather than forecasting from the present into the future, the model was started from 2021 using TEMPRO projections as its "base data", and ran in one year steps to 2056
  • the model covered the whole of the GB mainland , with a system of 38 zones: these provided more detail in the regions which might be directly served by the networks under consideration, and very little detail elsewhere.

The generalised costs of passenger travel were supplied from the transport modelling carried out by MVA Consultancy, so that the economic impacts were sensitive to the assumptions made about networks, services, speeds and fares (and potentially sensitive to assumptions about the responses of other modes and services competing with high-speed rail).  Costs for goods vehicle movement were calculated by DSC on the basis of road distances, assumed speeds and WebTAG cost assumptions.

The results of the model were used to calculate the net impact of the proposals on the economy of each region, and to calculate the WebTAG Wider Benefits arising from the better connections between regions.  These typically increased the direct journey time benefits by around 20%, significantly strengthening the case for building a network of high-speed rail lines.



David Simmonds Consultancy Limited is registered in England and Wales, company registration 04860878. The registered office is 10 Jesus Lane, Cambridge CB5 8BA