Transportation helped shape this great nation. From the earliest days, the farm-to-market road sustained the agricultural economy. As the country grew, toll roads, canals, steamships and railroads opened up vast areas to settlement, creating communities at crossroads and where rivers met roads. Transportation helped lead the country’s transition from an agrarian to an industrial economy. In fact, towns created along the inter-continental railroad are the earliest “TODs.”

With industrialization came urbanization, and with urbanization came transit’s growing influence. Streetcars, subways and the “L” helped small and large cities realize their economic and social potential. Compact, walkable “transit-supportive” communities were actually the norm – just not so named. Community, economy and mobility truly were in balance.

The end of World War II marked the greatest economic expansion in United States history, and with it came a radical change in the balance between transportation infrastructure and community form. The highway system became dominant, streetcars were abandoned in favor of the bus, and suburbanization became the norm.

Now, we are entering a new era defined by international and global economies, rapid technological change, natural resource depletion, climate change, a return to cities and a desire to balance sustainability’s “triple bottom line” – environment, community and economy.

Transit and Sustainability
Transit directly corresponds to the triple bottom line. It is environmentally friendly; relieves traffic congestion; fosters compact, walkable mixed-use communities; offers mobility options for all socio-economic levels; and promotes economic development and access to employment.

The manner in which sustainability is incorporated varies from one transit project to the next, due to the diversity in scale and type among project options, as well as a community’s particular needs. Three principal areas where transit makes an impact are planning, design and construction, and operations.

Transit Planning
Every successful transit project starts with a plan. Scale, and environmental and community impacts play crucial roles in the planning process. Sustainable transit solutions are developed through:

• Socio-economic Analysis – This identifies how a transit plan impacts job creation and household development.
• Public Involvement – The process is visible, accessible and credible, offering all stakeholders an equal voice in helping define the project.
• System Planning – Sustainable systems help shape regional settlement patterns, foster mobility and increase community interaction, and protect and enhance environmental assets.
• Environmental Documentation – Environmental responsibility includes proper documentation and permitting.
• Sustainable Urban Design – “Places where people want to be” result from sustainable planning and community design for transit corridors, districts and station areas.

Design and Construction
The design and construction phase manifests environmental and economic sustainability implications. For example, corridor and track development might include provisions for alternative delivery, recycling of construction waste, avoidance of negative environmental impacts and using recycled/composite materials. Site and facilities development should incorporate cost-effective, environmentally sensitive site work and construction. “Green”/LEED-certified stations, operations centers and administrative facilities are increasingly common. One such example is the Pentagon Metro station, which integrates Metro rail and bus terminals in a protected, pedestrian-friendly environment that meets security and accessibility goals and offers an inviting arrival experience.

Transit Operations
Significant opportunities exist to advance sustainable operations as well, from using less hazardous fluids to reducing greenhouse gas emissions. Environmental management systems facilitate policy development, help set goals and establish processes for monitoring performance and reporting results. Coordinating office, operations and maintenance facilities leads to operational and environmental efficiencies. Converting to non-caustic solutions and employing recycling programs can reduce hazardous waste. Further gains are possible by maximizing fuel efficiency of the transit system. This can be accomplished by employing new technologies and alternative fuels, making vehicle/mechanical adjustments and consolidating routes.

The Mode Makes the Difference
Different transit types bring different strengths and opportunities. A review of the primary transit types – heavy rail, commuter rail, light rail, bus rapid transit and streetcars – reflects the varied urban form/sustainability relationships.

Heavy Rail
Heavy rail is primarily commuter-oriented, and has high effects on land use. The principal impact area is up to a one-half mile radius (500 acres) from the station. Positive influences come from heavy rail’s capacity, speed, service frequency and accessibility. Often heavy rail is in a subway configuration. This allows direct, vertical access to the system, and offers great efficiency since it uses no additional real estate. Elevated stations, while less approachable than at-grade or subway stations, can be effectively incorporated into mixed use complexes. The high frequency of service is land-use supportive, and compact, walkable mixed-use results are possible. Located only in our largest cities, this mode promotes significant high density urban development. Communities such as Washington, D.C., (Metro), San Francisco (BART) and Atlanta (MARTA) take advantage of their transit systems by promoting and implementing transit-oriented development. In return, these agencies are able to structure joint development agreements that provide ongoing income.

The Pleasant Hill BART station in Contra Costa County, Calif., is a successful example of turning an office complex and regional park and ride garage into a truly walkable mixed-use community. The most important issues in the master-planned development were:

• The design of the future development on BART property;
• Vehicular traffic and access;
• Open spaces and greenways for pedestrians and cyclists;
• Maintaining parking capacity for BART patrons and local residents;
• Adding new services and facilities for area residents; and
• The proper mix of uses within the site.

The plan includes a large public plaza adjacent to the BART station, surrounded by ground-floor retail and offices, and town homes facing the Iron Horse regional bike trail with views of Mt. Diablo.

Commuter Rail