Funny, I just measured that 3 days ago for a cityscape project. Here in British Columbia, on Highway 97 north, the yellow lines are 3 inches wide with a 3 inch space between them.
The lanes themselves tended to vary a bit between 124 inches and 126 inches.
The parallel parking spaces also varied a bit, between 66 and 75 inches wide. The real shocker was the length of these spaces where they were marked in town. That distance varied between 120 and 140 inches, even on the same street!
I found city streets to be marked based more on the distance between buildings than anything else, so they come out kinda random.
Hope this helps,
SRT.