The psychology of supermarket trolleys: Why different stores have different types and sizes of baskets and trolleys

There's no better feeling than grabbing a trolley at your local supermarket and embarking on your weekly grocery shop. The initial emptiness of that trolley screams potential!

There's no better feeling than grabbing a trolley at your local supermarket and embarking on your weekly grocery shop.

The initial emptiness of that trolley screams potential! Potential delicious foods and meals and bargain buys.

Not a week goes by where I don't think about how lucky were are to have so much at our fingertips, albeit at much higher prices than previously.

Still, it's a testament to how savvy Australian shoppers are that we can adjust to constant increases in cost-of-living, while also ensuring our families are well-fed.

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I've only recently returned to buying majority of my groceries in-store rather than online because I missed doing it in person.

It was while choosing between a smaller and larger trolley at my local Woolies that I started thinking about the impact trolley choice has on my weekly spend.

And so, that is the topic of this week's Supermarket Sleuths: Trolleys!

In particular, I'm investigating why different supermarket locations have varying types of baskets and trolleys, and why some require coin access and other stores do not.

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It is important for supermarkets to have plenty of functioning trolleys because their sizes and availability directly impact how much consumers spend.

Mumpower CEO Christie Nicholas described this as one of many "friction points" for shoppers.

"Supermarkets have to reduce the friction points for mums to make it easier for her to buy and buy more often," she told 9honey.

"Otherwise she won't be able to spend as much."

I asked Woolworths about why their trolley fleets (that's what they call them!) vary from store to store.

My local Woolies has free-wire trolleys, yet two suburbs away they are coin-operated plastic green ones.

I've also seen traditional shopping baskets on offer at Woolies and then slightly larger baskets with wheels.

"Metal trolleys are still part of our fleet for the time being as they are very dependable, however they are slowly being replaced by the plastic trolleys which are lighter in weight and easier to manoeuvre," a Woolies spokesperson explained.

"They are also manufactured in Australia.

"Shallow trolleys are ideal for smaller shops and slide more easily into the self-service checkout spaces, allowing customers to more easily reach into their trolleys without needing to bend over as far, while the larger ones are great for a big family shop."

It was only recently that I discovered the smaller trolleys at Woolies can be wheeled over the counter at the self-service checkout space, and it's so incredibly helpful to be able to do this.

The smaller Coles trolleys offer this same feature.

Coles also offers trolleys in two sizes.

Once again, some stores require a coin to access them, which can be solved by one of these nifty gadgets that unlocks them for you, available at places like Etsy or your local hardware store.

Neither retailer explained why some stores require coins to access trolleys and some do not, but I'd guess it has something to do with the rate at which trolleys were being removed from stores and perhaps wheeled all the way home.

A Coles spokesperson explained the differences in the supermarket's trolley fleets.

"In inner urban areas, we would offer more of the smaller areas as opposed to outer suburb/rural areas, we would have more of the larger trolleys," they told 9honey.

"This is simply based on geographical location and demographic needs of our customers."

Then there are Coles' specialty trolleys, including "trolleys for baby capsules, twins, toddlers and people with limited mobility".

"If you don't see these trolleys, talk to the Customer Service Desk team," they suggested, adding that "some of our smaller CBD stores can't accommodate all specialty trolleys".

Aldi has always had coin-operated trolleys, however they do now offer freely-accessible baskets. But I usually just grab a free trolley from Coles or Woolies and use it at Aldi as well.

Consumer expert Adam Ferrier from Thinkerbell weighed in on how trolleys influence our grocery spends, explaining "all consumer behaviour is made up of motivation and ease".

"The easier it is to load up the more you'll buy hence retailers make it as easy as possible to get a very large trolley or basket to ensure you buy more," he explains.

He said customers in city areas "tend to do more frequent smaller shops whereas those in out less developed areas stock up".

Of coin-operated trolley fleets, Ferrier predicts these will be "faded out, especially as dollar coins are so hard to come by now".

While I had him, I asked Ferrier if it is true that shoppers who don't take their trolleys back to