Stain failure after first year

I built a new deck 2 summers ago with pressure-treated decking. Let the deck weather for 1 year and applied stain after the wood had dried out. I used Olympic Maximum semi-transparent stain + sealant.

Well, after 1 year the high-traffic areas are failing miserably. A majority of the deck still looks freshly stained, however the higher-traffic areas, near the door and steps, are looking very warn.

Is there an easy way to "touch-up" the warn boards or do I need to strip and re-stain the entire thing? I'm really hoping to avoid the long process of stripping the entire thing, letting it dry out and then restaining. I can see that taking a long time considering the unpredictable weather here in Michigan.