I think this is a mix of cultural/legal. In Switzerland (people tend to behave in a community-sane manner) and Czechia (strick enforcing) people seem to be sticking to the limits. In Poland it was usually 10-20kmph above the limit because "I drive safe", however recently a new law was passed that on the one hand unified limits (we had 50kmph during the day and 60kmph in the night for the within city general limits) and they increased fines for breaking the law and AFAIR number of accidents dropped quite a lot...