Why Seattle Has a Complete Streets Policy
- Advances long-standing City land use, transportation and environmental policy
- Supports safe travel for all road users
- Promotes active transportation and supports healthy communities
The underpinnings of a Complete Streets policy in Seattle have been in place at least as far back as the 1994 Comprehensive Plan. It defines the urban village land use strategy to accommodate a majority of housing and employment growth; articulates a strong core value of environmental stewardship; and includes transportation policies aimed at creating a balanced transportation system that provides alternative choices to driving. Specific direction includes, "provide a range of viable transportation alternatives, including transit, bicycling and walking," and "make the best use of the City's limited street capacity, and seek to balance competing uses." The most recent version of Seattle's Comprehensive Plan states that "Part of Seattle's growth strategy is to encourage people to use cars less than they do today. One way to do that is through the urban village strategy's goal of concentrating most new housing, jobs and services near one another in small areas, so that more trips can be made by walking, biking or transit."
There has been a great deal of research establishing a connection between street attributes and safety for road users. Analyzing crashes across the country, researchers found that fewer than two percent of pedestrians who had been struck by a vehicle died in crashes where posted speed limits were slower than 25 mph; where posted speed limits were 50 mph or higher, more than 22 percent of pedestrians who had been struck by a vehicle died. Looking at actual speed, with every small increase in speed, the likelihood of dying in a crash also increases - but at a higher rate. For example, 5 percent of pedestrians struck at 20 mph will die, but that jumps to 45 percent for cars traveling 30 mph, 85 percent for cars going 40 mph. The data show a 100 percent fatality rate for cars actually going 50 mph or faster.
Here's a chart from the United Kingdom (UK) Department of Transportation that shows similar data: 
Ensuring that all residents of Seattle can walk, bicycle and have easy access to transit as part of their daily routine could drastically improve public health. Although most people don't think of it as a determinant of health, our transportation system has far-reaching implications for a variety of health risks. Regular physical activity provides a wide array of health benefits, including reducing the risk of some forms of cancer, heart disease, stroke, obesity, high blood pressure, diabetes, and injuries. In fact, research conducted by the Centers for Disease Control and Prevention found that "obesity is linked to the nation's number one killer-heart disease-as well as diabetes and other chronic conditions." In King County over half of the adult residents are overweight or obese (about 770,000 people), and just over half (55 percent) report that they exercise moderately about 30 minutes a day, five times a week. In school-age children, 21 percent are overweight and 9 percent are obese. Equity is also a concern; compared to whites, the prevalence of obesity among African American adults is 60 percent higher.
The report also states that one reason for Americans' sedentary lifestyle is that "walking and cycling have been replaced by automobile travel for all but the shortest distances". Automobile travel also produces harmful exhaust that lowers air quality, harms respiratory health and contributes to global warming.