I first saw this article: https://www.atlasobscura.com/places/wellington-airport-runway
which intrigued me enough to go look at Google Maps to see the airport in question. I’ve done a bit of an exploration to try and understand the non-standard markings that are used on the runway. Take a look on Google Maps. There are markings (perhaps concrete rather than white paint) at both ends of the runway perpendicular to the centerline. My first thought is they are for some type of arresting system, but being as this is a civilian field, I doubt that is the case.
I apologize if there’s an obvious answer. I’ve never encountered it in the runways I’ve landed at here in the midwest (US).