Potholes are bad, drivers are bad, too much construction on the roads, roads are too narrow from all the construction, too many dead dogs, traffic sucks... and the thing that irks me most: expired registration tags. I see at least one car a day with tags from 2004. And there aren't enough cops to monitor the roads.
When friends warned me saying that Riverside has the worst of driving, including the smog and accidents, I'd say it's pretty accurate.