(Forbes) - One of the very first things you notice about the Napa Valley is how utterly, almost ethereally gorgeous the landscape is.

Shortly afterward, you notice how very long it’s taking you to move through that landscape… because you’re sitting in traffic.

Highway 29 and the Silverado Trail are two of the Valley’s main arteries for cars and cyclists to travel north to south. The problem – and a blemish on Napa’s wine country experience – is that those arteries are frequently clogged with traffic, adding pressure and stress to what is, to any reasonable outside observer, an otherwise bucolic environment.

Here’s the irony: it isn’t the tourists who cause the traffic jams.

It’s actually local workers, mid-commute, who add most to the congestion on roadways. They’re spending so much time in their cars and on the roads because they can’t afford to live where they work. Given the salary for jobs in hospitality and viticulture, especially in relation to the very high cost of living in Napa, workers are being priced out of the local real estate market. Which means they live further away, adding to longer commutes and to the congestion of traffic.

Traffic in Napa is an infrastructure problem with limited resolution in sight. Worse, the traffic overflows into a companion problem: housing. That’s the subject of our next post in this Napa series but for now, here are five main drivers behind the wine region’s traffic problem, from employment rates to demographics to shifting priorities.

Agricultural Preserve 

Napa’s agricultural preserve is both a blessing and a curse: thousands and thousands of acres of protected natural landscape. That maintains the first impression visitors have when they come to Napa – its beauty – but it also limits the potential for the development of key transportation and housing projects.