Guardrail and Planter

I suppose that the National Park Service owns the guardrails on 16th Street NW just north of the bridge over Piney Branch  Parkway, as being on ground belonging to Rock Creek Park. There are wooden guardrails elsewhere in the park, though none I remember as quite like these, logs set on posts:

Some of the logs are still sound, in that they aren't cracked with plants growing in them, but all are more or less splintery. There is a gap of about three feet in the rails, left as I recall by a young man who some years ago--I suspect he didn't manage the oblique left from Arkansas Avenue to 16th Street. Well, that missing rail served its purpose by keeping the car from heading into the ravine.