Do the billboard ads fund the road maintenance? I didn’t think they did. I thought people just bought land next to the road and installed signs there.

Does Google pay for your PC, power or internet connection?

No, but they do pay the costs of hosting/serving the videos, which I thought was the relevant analogy to the service being used when driving on a road and there being billboards next to the road.

Is the department of transportation owned those billboards and used them to fund the roads I would feel 0% more obligated to look at them.

Sure, but it would make the analogy valid.