Highway 29 is the famous stretch of road that runs right through the middle of Napa Valley. It is the equivalent of the main drag at Myrtle Beach, SC if you happen to frequent the redneck rivieria like I do.
I have spent a lot of time travelling to and fro on this road in the last couple of months (and not due to a drinking problem, thank you) as a result of a consulting project I am working on. Every time I look at the road signs, I am reminded of a fascinating person I met at a trade show who had a hobby of studying the highway numbering system. She could tell you a number of facts about any highway based solely on its number. When I asked her about I-40 for example, she said all major interstate highways are two digits and even numbered ones run from east to west. Higher numbered interstates are further north than lower numbers. Odd numbered interstates run north and south and there are even rules for numbering the beltways around them.
Since Highway 29 is a California state road, I wondered what the numbering scheme there meant. It appears that California tried to follow the logic of the federal scheme, with odd numbered highways indicating a north/ south orientation.
I have also learned that Highway 29 covers a total of 106 miles with an average of 60,000 visitors per day. That's a lot of traffic for a road that's not quite 30.