This is indeed an odd bug. We've encountered it only once before but it's not easy to reproduce. It appears to be related to using planar segments with Clipping, and we suspect the cause to be the Max boolean operations we use internally when using clipping paths. Another quick way to fix this is to give the pavement segments some thickness on the Z axis. I found that adding a Shell modifier solved the problem immediately.
I hope that helps, please let me know if you have any other questions or require further help.