O ran cynllun yr M4, ar gyfer gwaith datblygu roedd y gwariant, gan gynnwys arolygon amgylcheddol, data o archwiliadau tir a modelau trafnidiaeth sydd, er iddynt gael eu cynhyrchu ar gyfer gwaith ar y draffordd, yn ymwneud ag ardal helaeth yn Ne-ddwyrain Cymru.
In respect of the M4 scheme, expenditure was incurred on development work including environmental surveys, ground investigation data and transport models that, although generated in relation to works to the motorway, cover a wide area of South East Wales.