I’m currently working on a research project to collect a dataset of images labeled with the guard rails or no guard rails. And I was wondering if someone could point me in the right direction to get the dataset that would really help.
I was able to find through the blog that there’s a feature value “construction–guard–rail” that I could use to filter images but I’m not sure if that is still in the works given the new modification of v4.
As best I can tell Mapillary doesn’t currently support line features, including “construction–guard–rail” in either the web viewer or via the API. They are not mentioned in either of the following pages:
I’d love to be wrong on this point, and if anyone from Mapillary knows differently please let us know.
That’s a bit of a bummer for detecting guardrail using solely the Mapillary platform as there isn’t really a point feature that corresponds 1:1 with guardrail. It may be worth trying “Traffic Sign Frame” and maybe “Pole” since these objects are often surrounded by guardrail in the USA.
In lieu of a Mapillary only solution I know of another free dataset you should be able to use. The good people of Open Street Map (OSM) have mapped about 100,000 guardrails around the world.
You could use Overpass Turbo to download that dataset, draw a bounding box around each guardrail, and then download high quality Mapillary images based on those bounding boxes. It’s a bit messy and it’s going to require a fair bit of cleaning once you’re done with it, but at least it’s free.