The roof of my house has many vertical "streaks" in the asphalt
shingles, evidently caused by the removal of the light-colored granular
material from the shingles which exposes the darker matrix. The streaks
start in a small region then spread downward and outward for about a
foot - sort of like the splat of a juicy insect against a windshield.
Much of the granular material ends up in the gutters. This has mostly
occurred within the last year.

Is this normal wear-and-tear, or an indication that the shingles are
overly worn? The re-roof job is about 10 years old. None of the other
houses in the neighborhood show this, but ours is the only light-colored
roof. Otherwise everything is fine - no cracks, loose shingles or
leaks. We live in Marland, weather/sun not too extreme...

I greatly appreciate any advice,

Mike