I’ve only seen it a couple of times before, and IIRC, it was during the time of the protests where people were walking up the freeway ramps and/or threat of same. And I’m on the area freeways a lot up here.
This is a perfect time to re-check and replenish your SHTF bag in the trunk and at work.
Put in sneakers and leather gloves, in case you have to climb over rubble. Hornet spray, which is easy to aim and shoots 15 feet, is also a great aid in dealing with “pedestrians.”