Final answer:
Greyfields refer to abandoned industrial areas in decaying suburbs often located alongside transportation routes and associated with environmental issues. They represent broader challenges in urban development and planning.
Step-by-step explanation:
Greyfields are abandoned industrial areas in decaying suburbs. This term is used to describe spaces that were once developed and thriving but have fallen into disuse, typically as industries decline or move away. They differ from other forms of derelict urban land because their redevelopment can be impeded by entrenched infrastructure that is costly to remove or repurpose. As described in the concentric zone model, industrial and working-class residential corridors develop along significant transportation routes like rail and barge, which over time can lead to the creation of greyfields when these areas see a decline in industrial activity.
In regions flanking transportation routes, environmental racism or classism can be observed, with lower-income residents often living in close proximity to industrial zones. These industrial zones are associated with noise, bad smells, and toxic pollution. When industries abandon these spaces, they become greyfields, offering a glimpse into the challenges of urban planning and environmental justice.