||The DGH maintains over 4,793 kilometers of provincial highways, 3,358 kilometers of county roads and 2,625 kilometers of county roads used as detours for maintenance projects (not including Taoyuan, Hsinchu, Miaoli or Hualian counties). The DGH also supervises maintenance by local governments on 7,418 kilometers of county road, and has increased the length of provincial highways it maintains by 889 kilometers, or 23%, since 1991.
||The DGH maintains 2,709 bridges on provincial highways and 1,316 bridges on county road detour routes, for a total of 4,025 bridges. Since July 1991, 1,295 new provincial highway bridges and 322 county bridges were built, or a total of 1,617 bridges, representing an increase of 67%.
||The DGH maintains 270 tunnels.