As you said traffic lights in Europe are on the leading edge of an intersection. This may in fact be the simplest and most foundational bit of usability and user experience innovation the US could learn from Europe in intersection design.

1) Placing the signals on the leading edge means that the stop line is ~10 feet back from the intersection. If you decide to ignore the stop line, you can't see the signals. BAM instant conformance to proper road use.

2) Following on that, sitting 10 feet back from the intersection you can see everything in the intersection. You can see pedestrians crossing in front of you and to the right of you. You can see cyclists entering into the intersection and passing you far before you enter the intersection. As a ped or cyclist this makes intersections much, much safer.

3) As you approach an intersection, and the light switches to yellow and then red, there can be no doubt about the state of the light as you enter the intersection. You can't enter or pass through the intersection on a red light as you might in the US, because it will be red before you even get to the intersection. This seriously reduces running lights or flying through the intersection, making intersections much, much safter for motorists.