This paper introduces the FreightShare Lab Platform (FSLP) and its embedded business model, aiming to facilitate and encourage horizontal collaboration in freight logistics. The idea of the FSLP is to create collaborating clusters of freight operators, and corresponding collaborative operational plans, via specialised decision support algorithms and multi-fleet optimisation. Further, a gain-sharing business model embedded within the FSLP algorithms ensures that participants, mainly logistics service providers and freight operators, can retain their own profit margins and fairly share the efficiency gains from collaboration. A case study is presented, centred on a large UK freight operator, to evaluate the key FSLP algorithms in a realistic context. The results evidence the potential for significant financial and environmental benefits for industry and society.