California Explores Sustainable Transit

As published by civil + structural ENGINEER magazine civil-structural-engineer-mag-logo

By Tim Psomas, PE, ENV SP

In California, 20 counties that are part of the Self-Help Counties Coalition will fund more than $95 billion of voter-approved transportation investments by mid-century, investing $4 billion each year in essential transportation programs and projects. More than 80 percent of California’s population resides in these counties. Each county delivers voter-approved transportation sales tax funding for transit, highway, freight, bicycle, pedestrian, and other mobility programs.

Last fall, I moderated a panel on sustainability at the Coalition’s 25th Annual Focus on the Future Conference. The conference attracted more than 800 attendees, representing elected officials, state department of transportation leadership, contractors, engineers, and vendors. The panel was titled “How Santa Clara VTA (Valley Transportation Authority) and LA Metro are achieving the Triple Bottom Line in Sustainability.” The session described how the BART Silicon Valley Berryessa Extension Project and the Crenshaw/LAX Metro Line will become more socially, environmentally, and economically sustainable through systematic implementation of VTA’s and LA Metro’s sustainability programs.


Sustainability is a key consideration in the $2 billion Metro Crenshaw/LAX Line that will extend from the existing Metro Exposition Line at Crenshaw and Exposition Boulevards to the Los Angeles International Airport.

Successes Reported

Across California, senior transportation agency staff have been working to educate board members about sustainable concepts, getting them more comfortable and overcoming their concerns about “budget and schedule busters.”

Sustainability is a key component for Santa Clara VTA’s $2.3 billion, 10-mile BART Silicon Valley Berryessa Extension Project. The line will extend from Fremont, through Milpitas, into the Berryessa district of north San Jose. Sustainability is also a key consideration in the $2 billion Metro Crenshaw/LAX Line that will extend from the existing Metro Exposition Line at Crenshaw and Exposition Boulevards. The Line will travel 8.5 miles to the Metro Green Line and will serve the cities of Los Angeles, Inglewood, and El Segundo, as well as portions of unincorporated Los Angeles County.

During the panel, a number of successes in meeting sustainability objectives were reported. However, it is important to note that both projects included soft sustainability goals, nothing prescriptive. Contract terms did not require the contractor to achieve specific sustainability outcomes.


Sustainability is a key component for Santa Clara VTA’s $ 2.3 billion, 10-mile BART Silicon Valley Berryessa Extension Project. The line will extend from Fremont, through Milpitas (shown here under construction), into the Berryessa district of north San Jose.

Reducing Greenhouse Gas Emissions

Greenhouse gas reduction through reduced vehicle trips is inherent in transit projects. Increasing public transportation use and getting people out of their cars is the most effective way to reduce greenhouse gas emissions.

In addition, stations are being designed as multi-modal hubs to promote access by sustainable means, such as walking, bicycling, private shuttle, local bus, bus rapid transit, light rail, and carpools. To encourage accessing the station by these means, Santa Clara VTA stations are designed with amenities such as pedestrian walkways, bike paths, bicycle storage rooms, bus-only lanes, bus transfer centers, private shuttle areas, and a direct connection to the existing Montague Light Rail Station in Milpitas.

LA Metro’s stations are similarly designed to be accessible. A significant enhancement to the initial project mandate is current plans to finally build and complete the Crenshaw Line to the Los Angeles International Airport. This is a good example of finding the common ground for sustainability — social, environmental, and economic success on transit projects.


Energy strategies include increased energy efficiency on trains and in station operations. Metro is currently utilizing flywheel technology. The flywheel energy storage system is able to capture energy generated by trains as they brake into a station. Another flywheel installation, scheduled to be completed in summer 2015, will act as a voltage regulator. While currently one of the largest renewable energy users in the country, Metro continues to expand its solar energy portfolio to meet its 33 percent renewable energy goal by 2020.

More than two-thirds of BART’s power comes from clean hydro and renewable sources. Parking garages will have solar panels to offset electric power demands and charging stations for electric vehicles. Stations are designed with skylights and other light-permeable surfaces to increase natural light levels and take advantage of daylight, thus reducing electrical power demands. Variable-speed escalators are being designed for the Berryessa and Milpitas stations to reduce energy consumption. Energy consumption has become a monumental concern for the average homeowner as well. Consequentially, people are using energy comparison sites to help ensure peoples energy use is as efficient as possible.

Construction Opportunities

The panelists discussed a number of ways to increase the sustainability of construction activities. Excavated materials can be salvaged, recycled, and reused locally. Water conservation is realized when extracted groundwater can be reused for dust control. Construction logistics can be managed to reduce fuel use. And finally, sustainable objectives can be met by procurement practices that specify local materials.

On The Horizon

An important part of the panel discussion centered on the opportunities and challenges ahead for sustainable transit measures. It is critical to improve elected officials’ confidence that transit sustainability initiatives can be achieved within established budget and schedule parameters. It’s also important for agencies to look beyond immediate capital construction cost savings to sustainable features that reduce life cycle costs down the line in terms of operations, maintenance, and energy use.

To date, many transportation agencies have relied on the good will of the contractor, as opposed to specifying desired sustainability outcomes. As agencies get more confident and experienced, they may start to explore specifying sustainability goals in contracts. Sustainability outcomes are an important dimension in commissioning the project team. Leaving the implementation of sustainability strategies for major capital projects up to the design and construction teams is a missed opportunity for transit agencies. In the future, agencies will need to become more comfortable with the various parameters of sustainability and the possible impact on initial capital costs and life cycle costs in order to specify desired outcomes.

In addition, systems to document and learn from successes are still in the early stages of implementation. It is not clear how, without such documentation, future project teams inside the agency or in other agencies will learn from past sustainability efforts and results.

Because they are heavy energy users, transit systems have a large exposure to energy vulnerability issues such as reduced availability, service interruptions, or spiking prices. This has to be addressed in developing sustainability goals.

Resilience is another factor in sustainability, which translates into contingency planning for disasters, natural and otherwise. Sustainable projects need to be resilient in the face of power outages, floods, and the potential impacts of climate change.

And finally, sustainable transit projects should be “future proof” by looking into the future to accommodate demographic shifts and changes in commuting habits to avoid negative impacts on ridership, such as the disappearance of the huge aerospace workforce in South Bay that the Metro Green Line was originally designed to serve.

While it is clear that transit projects by their very nature are sustainable, it’s also clear that there are many ways in which these projects can further increase the number of sustainability outcomes that they identify and meet. Much has already been done and plenty of opportunities lie ahead.


Timothy Psomas, PE, ENV SP, is the chairman emeritus, Psomas, and chairman emeritus, Institute for Sustainable Infrastructure.

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