How do brownfields typically impact urban planning?

Brownfields are often characterized as environmentally contaminated and underutilized properties, which is the correct insight reflected in the selected answer. These sites pose significant challenges for urban planners because they often require remediation before they can be safely redeveloped or repurposed. The presence of contaminants can lead to public health concerns and necessitate complex environmental assessments, which are critical in the urban planning process.

As urban planners work with brownfields, they must navigate a series of regulations and potential liabilities, impacting project timelines, budgets, and community perceptions. Successfully addressing these areas can lead to revitalization of communities, transforming them from derelict sites into valuable assets like parks, commercial spaces, or residential developments, but the need to assess and remediate contamination is a primary factor in the planning process.

The other options do not accurately capture the nature of brownfields in urban planning. While brownfields can potentially be redeveloped into residential spaces or other uses, they are initially seen primarily as contaminated areas that hinder development until they are properly managed. Thus, the focus remains on their environmental status rather than their developmental potential until significant remediation efforts are undertaken.