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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.

Canaan Merchant was born and raised in Powhatan, Virginia and attended George Mason University where he studied English. He became interested in urban design and transportation issues when listening to a presentation by Jeff Speck while attending GMU. He has lived all over Northern Virginia and now lives in Burke.  


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ummm...I see your points about "traffic calming" in a supermarket, but all the things you just described (ie, endcap displays, narrow shelves, etc) are the things that make it suck to go grocery shopping - especially when there is more than, oh, say, 1 person in each aisle. Let's hope that the real world will never approximate my local Safeway on a Sunday afternoon.

by John on May 22, 2014 1:59 pm • linkreport

+1 for John

The real takeaway from the video is simply that people behave behind the wheel in ways that would be absolutely unacceptable anywhere else.

by NotDavidalpert on May 22, 2014 2:30 pm • linkreport

The most relevant example to the grocery store are the 20-items-or-fewer checkout lines. If shoppers with baskets are bicyclists, people with carts are drivers, and express checkouts are bicycle lanes, you will inevitably get the some people with a cart loaded full of groceries try to just the express checkout. Those same people will get similarly indignant about being told not to use the express checkout lane or claim ignorance of the rules.

by Adam L on May 22, 2014 2:48 pm • linkreport

That video is...awesome.

As for the needless exposition -- I'm more in line with John's observation. Those awkwardly assembled displays in the aisle (not the endcaps) -- they may be traffic calming, but I've wasted too much time in my life putting them back together after bumping into one or two, or a few....They present their own dangers, as do their road cognates. Moreover, the supermarkets with the narrowest aisles are really a pain to navigate. I tend to prefer larger markets, and even in the smaller stores, I'm actually far less likely to go down many aisles.

If the idea is that the narrow aisles will slow down traffic and cause folks to see more of the groceries, it's a massive fail. I can go to the big supermarkers and there will be people going up and down the aisles. If I got to say Grosvenor Market -- 99% of the traffic makes a circuit down the wide produce aisle, left past the deli and meats, and another left at the other end, where the baked goods and frozen foods are. Almost no one goes down the narrow aisles in between. They might as well be residential streets, because there's no commerce there. And, shoppers looking for the packaged goods in those aisles, probably look for them in other, larger stores.

by Fischy (Ed F.) on May 22, 2014 3:38 pm • linkreport

I think the narrow aisle analogy can be made. At Bestway (in MtP) or Progresso (also MtP), at Yes! (in AdMo), or any other small supermarket people tend to be a lot more careful, slower, and more courteous. You recognize the fact that you're not the only one "on the road". I never get a cart so I know I'm only getting as much as I can carry anyway. Even at Whole Foods (on P) I get a basket and although the aisle are a little wider (than those mentioned above) and they do have the traditional big cart, it appears most people choose the smaller, more navigable double-decker carts.

by dc denizen on May 22, 2014 3:50 pm • linkreport

The supermarket represents a system where there is one entity in control of everything, including the cart path, shelving, amount of food, checkouts, etc. Since they are in control and all impacts are internalized, they can design everything to the maximum benefit. One person mentioned aisles between too narrow as a frustration for moving around, but the supermarket wouldn't want to make them too wide as they would lose shelving space (shelve space is ultimately the most important part). The supermarket then can find the optimal balance.

The real world of urban development works much differently, with a long list of private investors and public agencies sharing/conflicting in power. I wonder if this system could work better if individual areas fell under the direction of just on entity, sort of like having Disney World running a town in one of its theme parks. A Utopian vision I'm sure...

by Chris Allen, PE on May 22, 2014 6:26 pm • linkreport

As a European, I can state that the difference is that, in Europe, misbehaving motorists are disciplined -- even in supposedly "crazy" places like Italy and Spain. Here, pedestrians and cyclists get tickets, while drivers get to block crosswalks, honk at bikes, and speed -- in urban environments -- over double the limit.

by James on May 22, 2014 8:15 pm • linkreport

Cute little video but I'm not sure how effective it is in the long run.

I will say this: In my view, the common aspect of supermarket behavior and road behavior is people's less than civil reactions to the poor judgements and actions of other's around. In the supermarket, regardless of aisle size, people seem to forget that other people happen to be in the store besides them. It's as if supermarkets give people permission to disregard others so they can just stand in the middle of the isle and not let anybody get through. And peripheral vision is automatically turned off the minute someone walks through the market door. I happen to hate grocery store shopping and I like to get in and get out as quickly as possible, only buying what i need for a couple of days or so. So these kinds of people really make me angry.

On the road, particularly the highway, it is mindboggling that people insist on cruising along in the left lane, leaving a long line of angry people behind them who cannot get by. Then when someone finally does squeeze by ON THE RIGHT, you can almost see the light bulb go off above the drivers head that tells them, "maybe I better get over." But not before pissing off everybody behind them.

by EB on May 22, 2014 8:20 pm • linkreport

In a supermarket, I don't like narrow aisles where people are likely to bump into me or block my way, or rude people.

The only time I like narrow aisles is at hole in the wall bookstores where they got so many books they're practically stacked to the ceiling, however that poses a problem for those with mobility issues, and I wouldn't like that same set-up for groceries.

by asffa on May 22, 2014 8:42 pm • linkreport

In the grocery store you can not hide behind a glass and steal cage that can rapidly depart a scene or situation. I think that drives the difference in behavior more than the design.

by RJ on May 23, 2014 8:14 am • linkreport

@James - yes and I'm sure you've seen this by now:

by DaveG on May 23, 2014 8:20 am • linkreport

@Chris - Do you want some unaccountable corporation running everything? And isn't Celebration, FL a bit like that?

by DaveG on May 23, 2014 8:23 am • linkreport

Entertaining video that says little to me about road design and everything about selfishness versus courtesy.

by ah on May 23, 2014 9:48 am • linkreport

It's really noticeable when you're on a bike. People will whip around you into the oncoming lane in order to get the red light faster or get to the stop light behind tons of other cars. I love when they do that and I'm turning and I can pass them in the parking lane and turn before they make it through the light.

by BTA on May 23, 2014 10:33 am • linkreport

@BTA - often times drivers pass me by squeezing by w/o crossing the center line even when there is no on-coming traffic, thereby passing too closely, like in the video. (Though in the video there was only one lane so no option to give more berth when passing.)

I don't get why drivers seem to respect the paint on the pavement more than my life in these situations. When I take the whole lane thats when i get a sociopath doing something really dangerous even in the absence of on-coming traffic when just going around me by crossing the center line would be really easy. What's wrong with people?

by Tina on May 23, 2014 1:03 pm • linkreport

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