The signs are to alert drivers as amphibians begun their spawning period. The montane brown frogs and common toads in a nearby forest would cross the road to lay their eggs in a pond.
However, many of the frogs were ran over by cars, especially during rainy days. Local officials hoped the sign could give the frogs better chance to survive.
Credits for trying, but…
I don’t think it will help much. The cars may stop for a minute or two, but there are going to have some frogs on the road at any given time during the season.
It makes little different whether the drivers stop, slow down or go at usual speed. The only option is if there’s an alternate route to avoid the area altogether.