I don’t know about you, but I rarely consider the streets and sidewalks I travel over unless they’re an impediment. Biking around Seattle I know where to veer past a specific pothole. I’ve found myself in a groggy rage having spilled coffee down my sleeve, tripped by a tree root uplifted section of sidewalk. My car is old and I know when a road is equally as pocked by time.
And yet, it’s easy to just feel as if roads happen (if one ignores the traffic revisions that we endure for years). A good number of folks reading this do not remember a time when new roads were built on or adjacent to the Hill. They were just there and unless you are a civil engineer, an urban planner, or a mass transit or bicycling advocate, you might not have considered them either.
Sometimes roads take us in directions we hadn’t considered. When I first pondered the natural history of roads, I had this quaint idea of delving into what grows in the cracks of the concrete. There are surely compelling stories here, but really, you can figure it out: roads are made of earthly materials and plants grow in and wear at said medium with their roots, which combine forces with other types of weathering. We’ve all probably seen a bokeh image of a tree growing out of rock in some misty locale. Give some seeds a few years without any bother and our streets and sidewalks would quickly begin weathering away, all manner of vegetation sprouting from the cracks.
Ultimately, I realized I didn’t really know what roads are made of. Where did the material come from? What are the environmental costs of putting in and maintaining roads? How long does a road last? These are all questions I recently put forward to folks at the Seattle Department of Transportation who endured such infantile questions about our city streets with grace. Continue reading