highway lines

I was driving on the highway the other day and I noticed in a way I hadn't noticed before the line (or multiple lines I guess) that tell us which lane we are in and drive over when we switch lanes. I began to wonder how long these lines are. I always thought of them as quite short but when I looked I began to wonder how long they actually were. when traveling at 100km/h it is hard to judge exact distance. I came up with the idea that the lines are probably about 8 or 9 feet each. When I asked my beloved partner (out of the blue) how long she thought they were she said maybe 2 or 3 feet to which we disagreed, examined the lines, looked at the lines seperating oncoming traffic and decided that they were longer. So i pose this question to my readers. how long do you think one of the white lines of the line divider are? and if you do think about it when you are driving, does your mind change from the original answer you have reading this before looking at it while driving. I have no idea how long they actually are. these are the things that I think of.