‘Maltesers’ were the answer to building a three-mile link road - set to be worth billions to Doncaster - across boggy ground.
Of the borough’s many projects, the £56m FARRRS dual carriageway has the biggest economic potential.
It will slash journey times to Doncaster Sheffield Airport and link a planned ‘inland port’ railhead with the M18.
Some say that after it opens in January, it will unlock £1.7bn of private investment, leading to 5,000 new homes and creating 24,000 jobs.
But none of it would be happening if engineers had been unable to build across low-lying land.
FARRRS links Junction 3 of the M18 to Parrot’s Corner south of Doncaster. It crosses four rivers and two railways.
A light honeycomb clay pebble, about the size of a Malteser, was used in some embankments to prevent the structure from sinking, according to project manager Nigel Morley of contractors Mott MacDonald.
Peel Airports, iPort developer Verdion and landowner Harworth contributed £34m to the road, with £18m from Government and £2m from Doncaster Council.
Some 450 businesses backed the plan.
Phase 2 - a one mile stretch from Parrot’s Corner direct to the airport - is set to start in mid 2016 and be complete a year later.
Sheffield City Region Local Enterprise Partnership has conditionally approved £10m of funding for the scheme, Mr Morley added.