The study evaluates various transportation policies designed to improve public health by reducing vehicle emissions, increasing physical activity, and reducing traffic accidents:
"Our analyses show that many of the policies in this document can have immediate, mid-term, or long-term effects. Installing streetlights, new sidewalks, and bicycle-friendly infrastructure can have positive effects that are felt immediately. Incorporating bicycle boulevards or greenways into comprehensive community plans will likely bring about changes over time. The health effects of these policies will also play out in different time frames.
In order for transportation policy to positively affect health, expanded education and relationship building with multiple stakeholders at various levels is necessary."
Thanks to Todd Litman