The rapidly increasing demand on power density levels of electric vehicle (EV) drive systems is pushing the boundaries of traction motor performance. Hairpin windings are becoming a popular option for EV motors due to their reduced DC losses and improved heat dissipation capability when compared to traditional random windings. In this paper, a comprehensive design approach of hairpin winding layouts is firstly presented. The flexibility and limitation of end-winding patterns is thoroughly investigated in terms of basic pin connections, special jumpers, transposition, parallel branches, terminal positions, phase shift, winding pitches as well as slot-pole combinations. To address the challenge of much reduced practical layout options with increased slot number per pole per phase, two novel hairpin winding designs are proposed. A 160kW, 18000rpm PM traction motor featuring the new winding layout with 54-slot, 6-pole is developed using a multidomain design platform which puts special focus on the conductor size optimization. The advantages of the designed motor are clearly revealed by comparison with the more traditional 48-slot, 8-pole counterpart. Finally, a corresponding stator prototype with the proposed hairpin winding is built to validate its manufacturability.