The road near Saint-Malo on the Brittany coast is to be closed to traffic from 15 January to 15 March by local council order.
Every year hundreds of toads and palmate newts cross it to go and mate in a pond in the Pointe de la Varde protected natural site.
Both the species are endangered species.
Last year about 1,000 amorous amphibians were counted around the pond in mid-February.
But a large number never got there, having been squashed by vehicles while crossing the road.
That led to a first ban on traffic for a month, which "managed to stem the amphibians' death rate and preserve their reproduction", according to the town council.