The second sub-criterion found under the Economy Criterion, concerns Wider Economic Benefits (WEBs) derived from the impact of transport upon agglomeration, and the underlying relationship of impacts of agglomeration upon productivity.
A set of suggested methodologies for appraisal of Wider Economic Benefits was published by the UK Department for Transport in summer 2005 covering a range of welfare and GDP benefits. Four possible further types of additional transport impacts were identified:
