 The motorway would have ended a short distance beyond the M25 on the Brentwood Bypass (A12).The alignment of this route was not finalised before the proposed airport at Maplin Sands was cancelled, but it would have matched the South Woodford-Brentwood alignment to Havering-atte-Bower.The M12 would most probably have then headed south-east and then south to pass east of Harold Hill parallel with the M25 as far as junction 29 where it would have turned east to run north of the A127 passing to the north of Basildon, south of Wickford and to the north of Rayleigh and Southend-on-Sea before heading out into the North Sea to the artificial island that was to be constructed on Maplin Sands for the proposed airport.