Despite clear production, environmental and economic benefits associated with the adoption of controlled traffic farming (CTF), its use in vegetable production is often constrained by the lack of suitable harvest equipment. A possible solution to that constraint is the use of Wide Span (WS) tractors, which would provide a mechanisation platform on which a wide range of production machinery could be mounted. Such machines are not commercially available, but a prototype developed in Denmark in 2013, and more recent autonomous developments in Canada in 2017, are indicative of future possibilities. Building on earlier work, modelling was done to estimate the economic impact of adopting Mixed-WS CTF, in which a WS harvest platform is integrated with conventional tractors, and WS CTF, based on WS tractors alone. Returns were calculated as income minus operating and ownership costs (including interest and depreciation). As no commercial adoption of WS tractors has yet occurred, modelling was done using conservative estimates of costs and returns applied to case study farm scenarios. Modelling results indicated median increases in average returns of up to 59 per cent. The most important cost factors to be considered were machinery capital costs and the impacts on harvest efficiency under CTF, while on the benefit side of the equation, crop yields had the most influence on modelling results.