Kevin DeGood | Center for American Progress

The McLean station of Metro's Silver Line on June 23 in McLean, Virginia.
The McLean station of Metro’s Silver Line on June 23 in McLean, Virginia.

Major public transportation investments can be transformative—reshaping communities, spurring economic development, and improving mobility. The new Metro Silver Line in Northern Virginia, which is an extension of the existing Washington, D.C., subway system, represents a major investment that will reshape the region for decades to come. Yet, the evolution from initial operations to a completed system that fully delivers on promised benefits takes many years and is not guaranteed.

Prior transportation investments and land-use decisions create a path dependency that often limits future change. Realizing the full potential of transit investments therefore requires a sustained political commitment to support development projects that increase ridership and offer an alternative to driving for all mobility needs.

When elected officials advocate for major transportation investments, they often promote a vision of a fully built-out rail system and communities that have grown and matured around each station. After all, accommodating future population growth and reducing roadway travel demand are important reasons for building these big projects. However, new rail lines don’t exist in a vacuum. Instead, they must operate within the existing built environment that was designed with the exclusive goal of moving cars at high speeds. And the challenges don’t stop with prior roadway investments. Read more