What a supermarket can teach us about road design
What do grocery store aisles have in common with our roadways? More than you might think.
Streetsblog recently posted this video from Norway which shows an aggressive driver using his techniques in the supermarket with his cart.
Many aggressive behaviors that we commonly accept on our roadways absolutely wouldn't fly in a store or other space where people gather.
The video notes that in Norway, 70% of cyclists have had to deal with aggressive driving. We certainly know what aggressive driving can lead to in the Washington area as well.
These days, when I go grocery shopping I can't help but think of paralells between our grocery aisles and features that engineers use in traffic calming and road diets. Many elements in a grocery store aisle resemble a calmed street and provide a glimpse of how someone's behavior changes when the road changes.
Shared space, narrow lanes, tight corners
If a grocery store aisles are too wide, there is is less space to sell items. Plus, the stores don't want people rushing through without having to at least glance at the products on the shelves. Most grocery stores have aisles wide enough for two carts to pass, but people do have to pay attention and navigate more carefully than they would in a wider lane.
Likewise, many many road diets reduce either the total number of lanes or in the width of the lanes. Besides slowing down cars in narrower lanes, such a change also frees up room for wider sidewalks or bike lanes.
But since aisles don't have special lanes for people with and without carts, maybe the closest parallel is the concept of "shared space," where all modes mix equally and drivers usually need to travel close to a walking pace.
In addition, the height of the shelves can mimic the function of buildings on city streets and create a streetwall. That creates the effect of an "outdoor room" and helps define a sense of place for an area.
Intersections in the grocery store are usually at right angles, and end displays can even be wider than the shelves in the regular aisle. This means that anyone entering or exiting has to stop and look both ways before proceeding.
Many street calming projects remove slip lanes that encourage speeding and cause drivers to ignore pedestrians. In their place, tight corners and curb extensions (often called bulb-outs or neckdowns) give pedestrians more room.
Obviously we can only take the analogy so far. There are as many differences as there are similarities. A grocery store and a state or local DOT have different goals; you don't commute through the grocery store.
But this does help illustrate how our built environment influences our behavior. The design of a grocery store aisle forces some cooperation and courtesy from all users, just like a road can induce people to drive at a certain speed (regardless the speed limit) and be mindful of other users traveling by foot or by bike.
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