Cuz,
You will find that most the UK street work is priced in linear metre runs, then the applied percentage increases with height etc. It's ship yards and offshore that tend to use M2 (even ft2) due to the amount hangers and dance floors that are built as it is priced on the boarded area only. Overseas, formwork/falsework and topside fabrication will normally use M3.
Cheers,
Phil.