The people I am preparing it for want them white and without any edges showing. I had the stripes in an earlier version. They showed up well but they were a hair too wide and they didn’t like how they looked grey when viewed at an angle (due to the shading). So I replaced them with new thinner stripes, but now I am having visibility in addition to shading problems. As you can see in the photo, they are sort of partially obscured. The color seems ok now that I have turned the shadows on, but that doesn’t solve the visibility problem. Any idea how I can get these to show up better? Or do I need to redo them (again)?
You’re seeing z-fighting between the stripe and the roadway, two faces of different colors in the same location vying for visibility.
To remedy this make a single stripe a self-cutting component so that it removes the underlying roadway wherever placed. Your dashed stripe is a row of these.