Only time will tell, but we may be near the end of the road building era in the U.S., and probably in Sonoma County as well. Nevertheless, there is a huge road infrastructure accumulated over many years that has to be maintained in perpetuity.

In the U.S., and to a lesser degree elsewhere, road networks evolved into a hierarchy of roads specialized by function:

Local direct property access
Collector gather traffic from local streets and feed it to the arterial system.
Arterial longer distance mobility and not intended to serve as immediate access to properties
Freeways fully grade-separated so no signals are required for traffic on the freeway. No direct access from property.

At the same time, where the street networks were once mostly a grid structure, they became more dendritic, or "tree-like", tending to force more traffic from local to collector to arterials, thereby causing the arterials to become congested.

Then came TND, or Traditional Neighborhood Development. A decade ago, Walter Kulash, one of several notable traffic engineers associated with the traffic aspects of TND, explained Why TND Traffic Systems Work.

Rural Roads

Sonoma County's rural roads are beautiful, yet sometimes hard to enjoy, especially from a bike or on foot. Creation of a system of Heritage Roads might be one solution.

City Streets

City streets can be made better for all users. Seattle published an informative guide a few years ago, Making Streets that Work, which you can download in PDF format (2.6 Mb).

Environmental impacts of increased road capacity

Implicit in the concept of installing HOV lanes to widen a freeway is the assumption that pollutant emissions will be reduced. Recent studies bring that assumption into question.

How will a road "improvement" affect air quality? A central question is how emissions change with traffic speed. For many years there has been an expectation that moving the traffic along faster will help reduce pollution. Well, yes, it was too good to be true. Read John Holtzclaw's article on how emissions change with traffic speed, in the Sierra Club's SprawlWatch website.




Like any road, freeways are a land use that facilitates transportation. Thinking of a freeway as a land use might lead to thoughts of the land that underlies them. Why isn't it taxed like other uses of land for private benefit?

Most roads provide access to adjacent or nearby property, so it might be expected that the value of access would be reflected in the value of those properties, not only for human travel, but for water, sewage, power and other utilities that utilize the road right of way. But freeways don't have this close connection. The land under them is a gift from the locality through which they run, to travelers from somewhere else. Although it might be easy to believe that the costs and benefits of these gifts are rather evenly distributed, they actually aren't.

Another remarkable idea has emanated from Professor Donald Shoup and his colleagues: to use congestion tolls on freeways, and distribute the toll revenues to the localities in which the freeways lie. The idea surfaces in Shoup's book, The High Cost of Free Parking.

In the middle of Chapter 19, “The Ideal Source of Local Public Revenue” — within a broader discussion primarily about curb parking revenues and land taxation — Shoup launches an illustrative argument using freeway tolls as an analogy to curb parking charges. The analytical background and other details of the proposal are left for Appendix G. (The book is, after all, about parking.)

The text of Chapter 19, sans illustrations, can be downloaded here . ( 401Kb PDF)

Appendix G, with graphics and tables, can be downloaded here . (220 Kb PDF)