The present disclosure provides new transportation design methods and a system that can improve road capacity, throughput, and travel safety as well as facilitate the current and future development of autonomous driving. The new methods and system basically eliminate all potential stopping, slowing down, and traditional crossing intersections in traffic. By mosaicking variously sized and shaped one-way loops in two-dimension and a myriad of ways and levels, the new design and system generally reduce possibilities of road accidents and utilization, reduce city pollution and improve energy efficiency, as well as encourage ride sharing and public transportation. The new design can always be compatible with existing streets and support progressive construction in phases at a controllable cost so it is practical in implementation.