They open up some great monitoring chances and they are always well organized. See my page on fire listening right here for more info. Any other time calls for law enforcement. The winter however, is the time to scan those cops and search for any new frequencies around. The weather here can get very nasty and it is great fun to listen to the police and CHP organize road closures and constant wrecks while cars run into ditches due to rain.
Heavy wrecks are rare though and that is a good thing.
There isnt much in the way of crazy drivers. If you are using an outside antenna, the Tehama County sheriff uses 154.740. That is used as well for Humboldt County sheriff's dispatch. Also, Butte County sheriff dispatches on 154.725 and they bleed over all the time. I usually tune my scanner to 154.745 to block all of that out.