dualling means the conversion of a road into a dual carriageway. Lexicurio rates it Sui generis — a strength score of 90 out of 100.
Etymology
From dual + -ing.
noun
- The conversion of a road into a dual carriageway“Way back in 1971, the Government of the day first published plans for a high-capacity road network, which included the dualling of the A47 from King's Lynn to Great Yarmouth.”