A systematic review investigating linear infrastructure effects on Urban Heat Island (UHIULI) and its interaction with UHI typologies

Urbanisation is a global trend resulting in more people living in cities. This has led to changes in urban morphology and microclimates explained by the urban heat island (UHI) effect. The UHI effect has been differentiated into four typologies that relate to the subsurface, surface, canyon and boundary influences. This paper presents a systematic literature review that explores the specific contribution of urban linear infrastructure (ULI), inclusive of the road network (flyovers, at-grade, and underground transport), rail (heavy and light) systems and utility corridors (pipe and electricity networks) to the UHI effect. 288 papers were identified within which urban linear infrastructure has been examined with respect to the UHI effect. The review reveals gaps in the research of the UHI with reference to how linear transport corridors influence the urban climate. Given the different forms of transport corridors, underground, at grade and flyovers, scales and locations, their effect on microclimates can be represented by a dynamic interaction of to the four UHI typologies. Given this complexity, this review provides evidence for researchers, urban planners, climatologists, and transport planners to more fully consider the role that urban linear infrastructure systems have on urban climates.