A free-flow toll highway is a toll , but without a toll gate .
Cameras located on gantries, installed along the highway, instantly recognize the license plate of the vehicle traveling and automatically calculate during the journey what each motorist must pay.
Free-flow tolls are gradually being implemented on our highways:

How to pay a toll in free flow?
• With an electronic toll
• At payment terminals accessible on foot in rest areas and service areas, in cash
• At a tobacconist or press house equipped with the Nirio system (published by Française des jeux) by bank card or in cash
• Online on the motorway company website by credit card
Please note: payment must be made within 72 hours after passing. !
In case of non-payment:

A question regarding free-flow tolls?
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Everything about free-flow tolls on the ecologie.gouv website page:
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