scousedon: This is very true in UK and other EU countries. I know of two people personally that have come to UK with licenses issued in other EU countries that had very simple tests and I am told in certain countries that we have a recpirocal agreement with that licenses can be simply bought with a bribe.
Not sure if there are different standards in USA that make it easier to get a license in certain states.
Different terrain/driving conditions in different states would seem to dictate that driving tests would vary from state to state. The only thing even approaching an equanimity of tests is the CDL (Commercial Driving License) required to operate Class A vehicles. And even with the CDL, only the written test is truly standardized to cover all conditions/situations.
The last driving test I took (more than 20 years and 2 1/2 million miles ago) was in Colorado, one of eleven Western mountain states in the U.S. Their "road test" was considerably more stringent than others I've since witnessed in other states.
When I worked for a company based in Illinois a few years back, one of my duties was to administer driving tests to new/potential drivers. Even though the drivers were expected to drive "cross country" and safely navigate any mountainous areas they encountered, there was no provision in the test which allowed me to judge "mountain driving skills" - Mostly because there are no mountains in Illinois.
Driving tests are, by necessity, varied according to the local conditions which one is likely to encounter.