One outside shoulder is blocked off for water exit. Ran into this problem with the OEM Falkens when worn halfway, too. The Conti HT's have 2 sides blocked, but both are fixable with my tire groover, the Conti being less noticeable when done.I recommend Kumho Crugen HT51. Great 70k mile tire, every customer I have recommended them to likes them. My dad runs them year round in Northern Michigan. Rate very similar on tire rack. They cost about $50 less per tire. Look at the two, treads are very similar.