Open up your models, HE urged

MODELLING

Highways England should be more transparent about its new economic model and regional transport models, according to the West Yorkshire Combined Authority. 

Highways England says its  national macroeconomic model will capture “some of the key mechanisms by which road improvements impact the economy, including raising productivity (agglomeration), enabling new developments and boosting employment” (LTT 05 Jan). 

The West Yorkshire CA welcomes the model’s purpose but says: “It has not been made clear how robust the economy model is, what scrutiny has taken place and what was the outcome, and how the model will be checked in the future to test model forecasts.”

It is also “unclear how the economy model will be used with  regional transport models”, says the CA. “Economic performance has an impact on transport demand and it has not been made clear whether there will be feedback loops with regional transport model demand models.

“It is also unclear how big shocks such as exiting from the European Union and single market will be explicitly modelled and used in demand forecasting and assessment of economic impact of road schemes.” 

To ensure consistency in appraising the economic impact of investing in the HE’s strategic road network and local roads, WYCAsuggests the economy model should be made available for local and regional authorities. 

Highways England now has regional transport models (RTMs),  covering the North (an area roughly north of Lancaster and York); the Northern Powerhouse (Liverpool/Preston/

Scarborough/Hull/Grimsby); the Midlands; the South West; and the South East. 

Says WYCA: “It has not been made clear how well RTMs model the local road network and take account of the potential impact of Highways England’s road schemes on such roads.”

How the effects of major rail improvements are incorporated in the regional models is also unclear, it says.