Security forces, including airborne gendarmes, are searching for the gang of about 15 “heavily armed and battle-hardened” men, who swooped on the vans at the Avallon toll both, 200 kilometres south of Paris, at around midnight on Tuesday.
There were no shots and nobody was hurt in the lighting hold-up and the booth was not damaged, according to prosecutors and the firm that manages the motorway, indicating that the robbery was the work of professionals.
The vans were found burnt and abandoned in a field near the scene of the crime.
Attacks on armoured vehicles transporting jewellery or cash often require special equipment, such as explosives and assault rifles.
There were a number of similar robberies in France at the beginning of the 2000s but the last major one was in 2009 when van-driver Toni Musulin made off with his vehicle and a booty of at least 11.5 millions euros.
About 9.11 million euros of the cash was found and Musulin gave himself up after 10 days on the run but the rest of the money has never been found.