Curious About White Line Potholes

Why do potholes proliferate where traffic lines are painted? I am no Chemical Engineer but it appears the paint is causing increased deterioration of the asphault. Am I the only one who has noticed this? - Bob, Plymouth

Why is the hot top on highways disappearing where the lines were painted on it.  This is really happening bad on 495 you can see it where the breakdown lane was painted, and the passing lanes were painted there's no hottop.- Wayne, Seabrook

You can see this problem on a lot of Mass. highways.  Mini-potholes just underneath the line markings.  We did a story about this some time ago and learned that the potholes are caused because of 2 materials that shouldn't have been combined.....the particular type of asphalt, and something called "thermoplastic" which was used to make the lines.  The Mass Dept. of Transportation says they didn't know they shouldn't use the 2 materials together and when they figured out that there was a big problem, they stopped (back in 2005).  But the damage was done.  Our nasty winters, road salt and expansion and contraction all combine to create the road mess.

So what are they doing about it?  Patching, patching and more patching.  It's part of their $2-million a year pothole repair work.  And it's only a temporary repair.  Of course, if the problem hadn't happened in the first place, they wouldn't have to do this and some of that money could go to filling up other potholes.

There won't be a real "fix" until each highway comes up for re-paving.  It's all an expensive problem.

I'm interested in knowing how many different highways you've seen this on.  I'll start....Rt. 24