I've been driving in the states for 12 years.
Coming here, I notice that the tests to get driving license are very complicated and difficult in comparison there.
However, the quality of drivers that these tests produced is worse.
80-90% of drivers on the road do not signal when they want to
a. change lanes
c. make a temporary stop to pick up cellphone
Why do you think this is? Maybe there is a cultural difference that I am not aware.