Why don't Garbage trucks spawn in cities skylines?

Recently, I suddenly got an issue which I can't understand. My garbage trucks don't spawn; the figure keeps on jumping between 0 and 1. My city is starting to die and I need help or else I can't play the game anymore.

This problem came out of the blue. I even tried with all of my assets and mods disabled but I still get the problem. I started to play with the budget but still nothing happens. It definitely has nothing to do with my roads because my roads seem to be fine because they are used by other vehicles. I even tried placing down dumps in the middle of the city but still the same.

Solution 1:

That tends to happen when you have areas the trucks can't access. Flickering between 1 and 0 indicates a truck trying to find a path and failing. Are you sure all your roads work?

Solution 2:

I had the same problem and looked for a solution for hours until I finally found the reason and wanted to share it.

My only problem was that I had a road connection in one corner of my map where I accidentally set up the turning arrows via the awesome traffic manager mod, so cars could not enter a small district.

Seems like all garbage collection buildings across the whole city were trying to find a route to that small area and all failing. All spawned trucks, that de-spawned instantly. Just fixing the arrows fixed the whole city.

Seems like other generic buildings, for some reason, also suffered from that problem. Industry not getting resources, commercial not getting wares. Not sure what mechanic exactly caused that, but I don't think you can directly see when those building have problems spawning their trucks as with the garbage facilities.