Thanks to the rapid growth of multiphase drives (MPDs), multiphase (MP) rotating electrical machines have gained popularity in the scientific community, demonstrating several advantages compared to traditional three-phase ones. Although MP rotating machines have been extensively studied in the literature, little research has been carried out on MP linear electrical machines and their application in the transportation sector. In this context, this article proposes a highly accurate and computationally efficient analytical model of MP single-sided linear induction motors (SLIMs) validated through comparison with finite-element analysis (FEA) simulations over a large interval of operational speeds (i.e., 0 \mathrm m \cdot \mathrm s^-1 łeq v_m łt 150 \mathrm m \cdot \mathrm s^-1 ). The proposed model, obtained by extending the one published in previous works by the authors, is used to analyze the performance of different MP SLIMs in terms of forces (i.e., thrust and normal force) and efficiency. A comparison with a three-phase SLIM is presented too. Furthermore, the effect of an iron appendix installed at the rear of the motor, which has been shown to increase the levitation force of SLIMs at high speed, has been added to the presented analysis. The results of the analysis demonstrate that an MP supply greatly affects the forces developed by the SLIMs and represents a solution to integrate propulsion and levitation (PL) functionalities into a single LIM for magnetic levitation (maglev) vehicles.