I've noticed as I've slowly moved west in the USA that there's a lot of variation in the design of roadways that can lead to differences in how people drive.

On the east coast, in older towns and cities, many of the roadways have fewer lanes, lower speeds and nothing but a double yellow line separating oncoming traffic. This leads to people routinely needing to use discretion about when to cross the line and when to make left hand turns. In more recently developed cities out west, I find that there are more, wider lanes, higher speeds, wide medians and "left turn on green arrow only" signals that tend to desensitize folks to the concept of driving slow, yielding and using discretion and, indeed, oncoming traffic. I'm way more cautious now in parking lots and streets without such features than I ever was before.