Definition of "realisation"

A widening of the M4 had long been mooted, and the Welsh Government had even earmarked most of the required £1.6bn funding for a new 14-mile, six-lane section around Newport. Then, in the face of opposition from environmentalists, came a realisation that similar road schemes across the world tend merely to encourage greater car use and therefore soon prove ineffective in solving the original problem.

2020 December 2, Christian Wolmar, “Wales offers us a glimpse of an integrated transport policy”, in Rail, page 56