An integrated self-supporting and deformation-resistant modular driver's cabin structure for mounting to the front end of a rail vehicle body and for providing a driver space and a windshield opening, is composed of a composite sandwich structure with a single, common, continuous outer skin layer, a single, common, continuous inner skin layer and an internal structure wholly covered with and bonded to the inner and outer skin layers, the internal structure comprising a plurality of core elements. The driver's cabin structure comprises at least: side pillars each having a lower end and an upper end, and an undercarriage structure at the lower end of each of the side pillars. The fibre-reinforced sandwich located in the side pillars is provided with several layers of fibres oriented to provide a high bending stiffness. The fibre-reinforced sandwich of the undercarriage structure is such to transfer static and crash loads without flexural buckling.