Frisia planned and proposed railway lines. Future rail corridors, new route proposals and long-term network expansion projects before construction begins.
Frisia railway lines formally proposed or in planning stages: routes announced, studied or included in national and regional transport plans but not yet under construction. Ranges from rail projects with confirmed funding to long-term corridors still in feasibility study. Shows the intended direction of future network growth — which cities are targeted for new rail connections, where high-speed rail networks have planned extensions and which corridors are being considered for entirely new alignments.