All transportation systems have the ability to transform human settlement patterns, which can affect a range of social, economic and environmental issues. Considering investments in rail infrastructure have increased in recent decades (Bureau of Transportation Statistics, 2007; Israel & Cohen-Blankshtain, 2010), it is important for planners and researchers to understand how these rail systems influence land use, metropolitan development patterns, and population migration. The following paragraphs summarize the studies and their findings.

The Effects of Commuter Rail Establishment on the Relationships between the Built Environment, Travel Behavior, and Residential Self- Selection (RSS): To help regional and transportation planners better understand the role that commuter rail plays in directing intra-regional development, this chapter provides a longitudinal investigation of the influence of commuter rail on surrounding neighborhoods’ RSS, travel behavior and the built environment. We first analyze the role of commuter rail establishment in influencing change in neighborhood-level demographics, housing and economics (signs of RSS), and travel behavior. Second, we compare surveyed commuter rail riders to residents of the commuter rail stations’ host and neighboring areas. The results indicate that the development of commuter rail does not alter the host tracts in any of the characteristics observed, but rather suppresses population growth in neighboring tracts. Paired with direct evidence from a commuter rail user survey, we conclude that the use of commuter rail is more likely influenced by the built environment than by RSS.

The Effects of Commuter Rail Establishment on Population Deconcentration: Research to date has not established the efficacy of commuter rail systems in attracting migrants most likely to use such an amenity. Through the application of a modified population deconcentration model, this chapter finds that the provision of a commuter rail station significantly increases neighborhood-level out-commuting and gross migration, which signals success in attracting migrants requiring commuting infrastructure. These findings also signal that commuter rail encourages regional population deconcentration, but the evidence is insufficient to form a conclusion and the evidence from Chapters 2 and 4 signal otherwise.

Developing an Agent-Based Model (ABM) For Estimation of Land Use Changes around Commuter Rail Stations over Time: This chapter improves the understanding of commuter rails’ effect on future land use changes through spatial interaction modeling. In particular, we develop an innovative agent-based model (ABM) that allows us to estimate and visualize the probability of land use changes per parcel based on proximity to commuter rail stations, freeway exits, and the region’s central business district. Briefly, this chapter concludes that the development of a commuter rail station is statistically significantly associated with decreases in single-family residential land use near the station, which is met by increases in multifamily and mixed-use development. The spatial effects of stations on individual land uses vary by land use type, and no generalizable area of influence could be established.

This report points to potential future research, as well as implications for planning practitioners.