arch blue bridge centre city contemporary cross dundee footpath glass modern over pedestrian rail railway span steel stylish tracks walk walkway lighting purple grey greyscale monochrome building buildings bus buses construction control detour development double-decker buses empty equipment excavation excavations excavator fences fencing MRT overhead property redevelopment redirection roadwork safety Singapore space stairs steps temporary traffic vacant blocks abandoned angles appearance cut-off derelict direction disconnected disused hard hardened historic iron large left light line metal movement neglect neglected old outdated perspective perspectives rails railways reject rejected rusty scrap sleepers solid strength strong transport waste