Named for the German mathematician whose formulae first explained it, “Braess’ Paradox” describes the phenomenon by which adding links within a network somehow reduces overall performance.

It is most often applied to traffic management to show how adding lane capacity in a road system can by itself result in slower traffic and higher costs for individual motorists. A related and road-specific phenomenon called “induced travel” – the shift in individual driving habits and influx of hopeful motorists caused by the presence of new lanes or routes, filling those lanes up overnight – explains what would otherwise seem highly counterintuitive.

The paradox is worth considering as the island begins a new round of 20-year transportation planning – it actually guided, if not by name, our last round of planning in the early 1990s. At that time, islanders found consensus on two key points:

1) Highway 305 traffic may be bad, but we don’t want to see the highway widened, and 2) if highway traffic gets worse, we still don’t want to see it widened – we’ll just relax our expectations instead.

“We can’t build our way out of congestion,” was how we expressed it at that time. But the resolve of 10 years ago will be tested as we re-evaluate the city’s traffic plans, beginning with a workshop next Wednesday evening at the high school commons. Amongst the challenges to be considered is a

highway corridor that, without some changes on or around it, will become a wall dividing our community – impermeable, impenetrable, too busy to get across or perhaps even on.

Engineers in the employ of the city are already at work, and a one-day “snapshot” of afternoon traffic leaving the incoming ferry offers some guidance. About 23 percent of vehicles counted were registered to owners in Kingston and North Kitsap (not counting Poulsbo). That suggests islanders should take a proactive role with Kitsap Transit as it works to restore passenger-only ferry service that the state is about to jettison. Kitsap Transit’s plan (which could go into effect in mid-2004) would finally see cross-sound service between Kingston and Seattle, shifting a burgeoning traffic burden that a four-lane Highway 305, for example, would only invite.

But islanders use the highway as well – two-thirds of the vehicles crossing the bridge every hour are from Bainbridge. And we may have to consider modified interchanges or grade separations for access. Anyone for new asphalt? What would make you change your mind?

And what of our other roadways? New residences, even under current zoning, will tax our arterials and neighborhood streets over time. Options being offered for consideration include links between some roads that now dead-end. Those proposals may give way to another paradox eternally faced by planners: While the benefits of improvements tend to be diffuse, inconveniences and detriments – and opposition – are highly localized. Call that the “BANANA Paradox” – how to make improvements of any sort, despite a “Build Absolutely Nothing Anywhere Near Anyone” ethos.

Times change, populations grow. Our traffic can get worse by doing nothing; it can also get worse by doing something.

There’s a quandary for islanders to consider.