Introduction

‘M4 to Wales - and prosper!’ A history of a motorway

“…There was an assumption that the bridge had made Wales more attractive as a place for investment, not least because managers could move around more easily. 84 But the impact of this may have been to increase Wales's reliance on branch plants, something which was a structural weakness because in times of contraction these factories closed first. Moreover, it was difficult to disaggregate the impact of the bridge from the impact of the development grants available in Wales.…”

“…87 Overall, economists were uncertain of the bridge's precise benefits to the economy given fluctuating costs, wider economic conditions and traffic levels, but early nineteen-seventies estimates were anything from £99.8 million to £273 million. 88 Such figures were always open to interpretation because they relied on valuing time saved and estimating savings on vehicle maintenance from better roads. Although both government and industrialists argued that road links were key to industrial development, the hard evidence that the motorway network was decisive in where industry located was less certain and contemporary investigations now argued for more limited benefits.…”