Travel Advisory: We were travelling in Shasta County (which includes Redding and Lassen Volcanic Park). The speed limits change constantly without notice. We were doing the "average" speed, only to come down a hill and be stopped by a state trooper who was sitting there, waiting. He told us that the speed limit was ten miles less than we had been doing (neither of us had seen a sign; and keep in mind that we were sight-seeing, so we had no interest in speeding intentionally). We got a $200 fine. The officer offered no caution, but did note that we were tourists and not likely to contest the fine in court. When we stopped at a hotel in Redding (we didn't want to give the county more money, but we were exhausted having spent the day hiking), we spoke to two other people who had also been caught in speed traps. Bottom line: go to Yosemite or Death Valley, they value tourists there.