made up 61% of the emissions from road transport (68 MtCO2e), followed by Heavy Goods Vehicles (HGVs) (18% of road transport emissions, 19.5 MtCO2e) and vans (17% of emissions, 19 MtCO2e) [13]. Transport contributed a substantial portion of these air pollutants to the UK's domestic total: 34% of NOX emissions, 13% of PM2.5 emissions, and 11% of PM10 emissions came from transport in 2019 as shown in Figure 1 [13].

The environmental impact of freight distribution in cities has been observed as disproportionate to the number of vehicles: Whilst about 20% of road vehicles are light vans or heavy good vehicles (HGVs), they generate a disproportionate volume of key pollutants, as shown in Table 1.

Diesel is the predominant freight fuel and therefore the major contributor to nitrogen oxide pollutants (NOx) and particulate matter (PM) - the main causes of poor air quality. The health impact of freight on citizens due to poor air quality in the UK has been known and has become increasingly controversial and driven both national and local governments to consider interventions to limit commercial vehicles, especially those using diesel [14–17].

The Urban Freight Research Roadmap 2014, developed by two European Technology Platforms (ETP)2, noted: “Therefore, a holistic approach should be followed to understand what can be done upstream the supply chain to optimise urban logistics. But the peculiarities of cities and the differences [...] also call for a focus on the urban logistics itself. Different business models, new processes and technologies should be researched and implemented.” [18].

Work has tended to focus on the transport chain, regulation, and the technology of operations. Urban freight transport has been seen as notoriously ‘difficult to organize, difficult to modernize’ [19], and can be described as a classic ‘mess’ in systems approaches terminology [20].

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