Diversion, or not?

One week ago I wrote about an accident where a lorry crashed into a house front, see here. Due to the state of the house the street in front of the house is closed for all traffic. The vibrations generated by (heavy) traffic might cause the house to collapse.
So what is done? A diversion is set up around the village itself (in greater distance and also one closer to the village). There are signs telling the drivers about the diversions.
But who reads those signs? I watched at this point and counted the cars: nearly 50% of them continued their way as if there was no sign whatsoever. Many of them find (illegal) ways through very small roads.
Others have to return and then take the correct route.
Yesterday a driver of a big lorry with two garages loaded tried his luck too. He drove up a 18% hill. And was stopped by other drivers. He had to drive back that narrow and steep road, but was not able to. Instead, he tangled his trailer and then could not get away at all, without major help.
It seems like traffic signs are considered suggestions....