I found a few interesting oddities in a brand new report (pdf) on commuting from Washington’s Office of Financial Management. The survey-based report describes how people in 8 different regions of Washington get to work or school.
Not surprisingly, King County does the best overall for alternative forms of commuting. Less than 78 percent of King County residents get to work (or school) by car, truck, or van. And of those, less than 85 percent drive alone. The Tri-Cities region does the worst: more than 92 percent of commuters drive.
But when it comes to walking, King County places a distant third. Second place goes to "North Puget"–Island, San Juan, Skagit, and Whatcom Counties—where 5.5 percent of residents commute by foot. But easily the state’s leader in walking is the region called "East Balance"–the low-population rural counties of eastern Washington (and not including the counties that house Spokane, Tri-Cities, or Yakima). Nearly 1 in 10 commuters gets to work or school on foot in Washington’s cowboy country.
My guess is that the relatively high rate of walking in rural eastern Washington is due to the colleges in the region—Central Washington, Eastern Washington, Washington State, and Whitman—where students, faculty, and staff live close enough to campus to walk. If my hunch is right, it would confirm what many urban planners believe: that residential density is a close correlate of alternative transportation. While the vast counties of eastern Washington are generally low density, the academic hubs around colleges and universities tend to be medium- to high-density (and also usually boast a good walker-friendly infrastructure).
Walking also appears to be at least mildly correlated to commute time for Washington residents. "East balance" commuters have the shortest commute time—17 minutes—followed by "North Puget" residents with 20 minutes. King County and "Puget Metro" are tied for the longest commute time—27 minutes—while Clark County commuters in the Portland region are runners up at 25 minutes.