E-commerce and
personal
mobility

The substitution hypothesis

From a mobility point of view, it is more efficient for a few vehicles to make several round trips (i.e. the case of online shopping) than for a large number of vehicles to make individual trips to and from stores (i.e. the case of physical shopping). Early studies compare the two ways of shopping, assuming that online purchases replace store trips for physical purchases. These studies follow the principle of substitution.

The figure left illustrates this comparison. In accordance, many studies demonstrate substantial savings in traffic and negative transport side-effects, notably emissions. Cairns (2005), for example, evaluated international evidence related to switching from store-bought groceries to e-groceries and found reductions in vehicle-kilometres by 70% to be realistic. Much later as e-commerce became more a reality, Wygonik and Goodchild (2014) reached similar conclusions: for everyday purchases, personal travel generates more vehicle-kilometres than online deliveries by truck. Yet, they also generate higher levels of certain pollutants. In Europe, however, vans instead of trucks are the most common vehicle type to deliver online orders (Allen et al., 2018). Consumer shopping is also done through walking and cycling (Hagberg & Holmberg, 2017), significantly changing the impact of substitution.

A review study by Mokhtarian (2009) shows that while internet-usage and mobile phone penetration increased tremendously from 1984 to 2004, annual kilometres driven per driver increased by 34% over the same period of time. Between 2000 and 2017, strong increases in goods transport also characterise European roads, while passenger-kilometres remain somewhat stable (EEA, 2019). Such statistics undermine the “substitution hypothesis”.

Yet more recent surveys in France and the United States indicate a stabilisation in personal mobility for shopping. In France, the share of trips to large supermarkets (“hypermarkets”) increased until the beginning of the 2000s, but this evolution has come to a stop. The findings of the 2018 transport survey in the Île-de-France region surrounding Paris show a decline in travel between homes and stores: from 5.5 million trips per day in 2010 to 5.3 million trips per day in 2018 (Île-de-France Mobilités, 2019). According to the report, this is the result of two opposing trends. The first is the increase of everyday purchases in proximity supermarkets. The renewed interest in smaller stores can be partly explained by the investment of large retailers in the proximity segment, many of them from the same groups (e.g. Carrefour, Casino). The second is the decrease in occasional purchases that are now made via the Internet. In the United States as well, the most recent National Household Travel Survey shows a significant decrease in the number of personal trips for three major purposes, among which shopping. About one-third fewer trips for shopping and errands are reported in 2017 compared to 1995 (Mcguckin & Fucci, 2018).

Complex consumer behaviour

The impact of e-commerce on consumers’ purchase behaviour is complex. Cullinane (2009) discusses four ways in which e-commerce and mobility potentially relate. Next to substitute or replace, e-commerce can modify consumers’ travel behaviour, generate more shopping-related travel or add non-shopping related travel.

This is where “omnichannel consumer behaviour” comes in, designating consumers’ simultaneous use of physical stores and online sales channels to carry out a single purchase. Considering consumers’ shopping journeys as a five-phased process, consumers can carry out product research; product testing; actual purchase; product reception; and product return (Buldeo Rai, 2019). These different phases constitute consumers’ “path-to-purchase” and can be executed on separate times, in different ways or not at all (in the case of research, test and return). In this way, the omnichannel model that retailers have developed is fully grafted onto consumers’ behavioural patterns. Yet consumers behaved omnichannel long before these new retail models saw the light: researching online before making a purchase in-store or testing products in-store before buying it (lower-priced) online. International consumer surveys demonstrate that about 38% of United States consumers (UPS, 2016) and 64% of Belgian consumers (bpost, 2017) shop in fact omnichannel. Today, numbers are probably even higher.

Omnichannel consumer behaviour both modifies and generates mobility. Modification of shopping-related travel occurs through “click-and-collect”, also called “buy online pick-up in-store”. This process entails to research and purchase items online, while store visits serve only to receive the purchase. Online browsing, in which consumers study the assortment, compare product characteristics and verify reviews, followed by a purchase in-store, can modify shopping-related travel as well. For example, by encouraging visits to other, more specialised stores. Next to modification, online research can also cause travel generation, as consumers become aware of products they would like to purchase and would not have come across otherwise. In another way, research behaviour can generate travel when multiple stores are visited on multiple trips before making a purchase, either online or in-store.

A new service called “ship-from-store” generates travel as well, as it facilitates in-store consumers to receive their purchase at home instead of carrying it home themselves. This system is particularly useful when items are voluminous, heavy or out of stock. It can also be introduced to enhance customer convenience. In this way, “ship-from-store” generates delivery trips next to consumers’ store visits, doubling mobility. The figure below visualises the results of a survey by SprintProject and GS1 among 2000 consumers in France. It shows that consumers appreciate delivery-services after an in-store purchase, but more stores should offer it (SprintProject, 2020).

Retailers are experimenting with several types of technology along the path-to-purchase, that have substituting, modifying or generating mobility effects. While the worldwide web offers consumers research options to an unprecedented extend, retailers aim to enhance the research process in-store as well by introducing virtual screens, self-service kiosks and digital signage. Contrary, stores outshine online solutions when it comes to testing and trying out products and receiving “humanised” information. To address this disadvantage, e-retailers offer innovations with various levels of technological advancement to virtually try out clothing and accessories: from picture-uploads and digital avatars to augmented reality enabled fitting rooms.

Less technologically advanced solutions are home delivered test-sets to try a variety of items before making a final choice and campaigns that encourage “fitting rooms at home” involving surplus orders and excess returns. Supporting out-of-store purchases are digital home assistants and other remote retailing technologies that are building on augmented reality, virtual reality and touch technology. In-store purchase support is created by contactless payment technologies, enabling to pay mobile or automatically. Technologies related to product reception and return are discussed in the next section, on goods mobility.

Regardless of the various ways in which consumers combine physical and web-shops for their purchases, e-commerce affects mobility by facilitating overall “shopping fragmentation”. This concept describes the decomposition of the activity of shopping into a large number of different sub-activities, some of which are carried out physically and others electronically from a variety of different locations. In concrete terms, instead of one trip to the shops to purchase a selection of items, e-commerce enables to purchase each of these items at different times of the day and at different companies. Consequently, a single store trip is replaced by several deliveries (although these deliveries can in turn be grouped together and organised into tours).

The immense adoption of smartphones has further enforced the fragmentation process. Purchases are possible at any time of the day, “including when we are at work, using public transport, waiting at airports and even climbing up mountains” (Cullinane, 2009). Non-food purchases might be more receptive to fragmentation, it has been argued less important for food and groceries shopping (Cairns, 2005). However, research bureau 6t (2018) discovered more shopping-related trips amongst e-grocery shoppers: the more intensive the online shopping practice, the more frequent trips to the grocery store. What’s more, their survey established that only 3% of both Parisians and New Yorkers no longer take trips to the grocery store since they have started shopping for groceries online. Evidently, e-commerce has changed consumer activity paths, which are no longer solely polarised by precise, grounded locations (such as hypermarkets, local stores) but fragmented in space and time (6t, 2018).

Discussing personal mobility in the light of e-commerce impacts, requires zooming in as well on consumers’ travel choices. When engaging in shopping trips, travel distance; modal choice; vehicle type; and number of combined activities in one trip are key. Simply put, trips by foot or by bike are always preferred over e-commerce induced delivery trips and in this case the substitution of purchases by e-commerce is negative for the environment. Yet long travels in diesel cars for a single purpose are better replaced by an online purchase, in which case e-commerce is preferable to traditional commerce. Ultimately and beyond the sole sphere of e-commerce, resorting online to make purchases potentially frees up time for other activities that involve travel.