Just like moving next to an airport and then complaining about the noise. Those same victims likely received a discount on property price as compensation.
Seeing as it's Prague, the chances are very good that the houses were built long before cars were a thing.
And I don't even understand your assumption - of course you should be complaining about noise levels if they are unacceptable, no matter if you just moved next to an airport or if you lived there for the past 50 years. Same as moving next to a pub or a night club - why does it matter that you just moved next to it, if the local laws governing noise levels at certain times existed for decades? Either the club/pub/airport brakes those laws or it doesn't - your personal length of habitation in the area has nothing to do with it.
Most of the roads I'm talking about are not near houses and/or underground. There are several roads where it indeed is noise related, but these ones are 60km/h only.
And I don't even understand your assumption - of course you should be complaining about noise levels if they are unacceptable, no matter if you just moved next to an airport or if you lived there for the past 50 years. Same as moving next to a pub or a night club - why does it matter that you just moved next to it, if the local laws governing noise levels at certain times existed for decades? Either the club/pub/airport brakes those laws or it doesn't - your personal length of habitation in the area has nothing to do with it.