The Charlotte metropolitan area is one of the fastest-growing and most economically dynamic regions in the United States. Since 1990, the area has grown from 1 million residents to its current population of more than 2.3 million. With this growth, however, has come additional congestion. In response, the Charlotte Area Transit System (CATS) has sought to expand public transportation services, including the construction of light rail transit.
The National Environmental Policy Act (NEPA) provided CATS with a process to identify the most appropriate route and transit technology combination as well as other design elements and construction practices to meet local mobility needs while minimizing social and ecological impacts.
In 2007, after years of planning and building political support, CATS opened its first light rail segment known as the LYNX Blue Line, which extends south 9.6 miles from downtown Charlotte. Within the first year of service, ridership doubled the preconstruction forecast, providing more than 18,000 weekday trips.
Following the success of the first segment, CATS and local elected officials pushed to extend the Blue Line 9.4 miles northeast to the University of North Carolina at Charlotte. Upon completion in 2018, the Blue Line extension will provide more residents with a safe, affordable, and efficient alternative to driving. Additionally, the extension will support increased residential and commercial density along the corridor, as called for in the city’s updated land use plan.
Before deciding to extend the Blue Line, however, CATS conducted a full alternatives analysis as required under NEPA. This included a review of a wide range of options, including rapid bus, light rail, streetcars, and commuter rail. From this broad set of possibilities, CATS narrowed its analysis to those options that were not “fatally flawed from an engineering or environmental perspective or would be unlikely to meet project goals and objectives.”
CATS conducted detailed analysis of several rapid bus and light rail alternatives as well as one streetcar option. The analysis determined that “The BRT [bus rapid transit] alternatives would serve existing land use patterns better than the light rail alternatives, but light rail would have more potential to support the desired shape of future development.” Thus, CATS used the transportation and land use goals established by the city of Charlotte to inform its NEPA purpose and need statement, which—along with other factors such as cost and ridership—served as the basis for analyzing project alternatives.
Initially, CATS selected a light rail alternative that would have included 13 stations, extending 10.6 miles northeast from downtown. However, due to the severe economic slowdown created by the Great Recession, CATS decided to reduce project costs by cutting two stations, scaling back structured parking, and shortening the line by 1.2 miles. In 2011, CATS adopted the revised light rail design, finding that it caused “the least damage to the biological and physical environment, while best protecting, preserving and enhancing historic, cultural and natural resources.”
As intended, the NEPA alternatives analysis process allowed CATS to answer the macro question of what project should be built to advance the defined local purpose and need. Next, CATS used NEPA to answer the micro question of how to deliver the project in a sustainable manner.
As part of the review process, CATS conducted a detailed traffic impact analysis of 55 intersections along the rail route in order to identify where the line should be grade-separated from existing roadways. For urban rail lines, grade separations affect safety, train run times, cost, intersection delays, and traffic spillover to adjacent intersections. The CATS analysis determined that the extension should include grade separations at all major intersections, railroad crossings, and entry and exit points for U.S. Route 29.37 In total, the Blue Line extension includes 11 new grade separations. For instance, the inclusion of a grade separation of the light rail line with 36th Street will allow intersection performance—known in traffic engineering terms as “intersection level of service”—to remain unchanged at the intersection of 36th and North Davidson.
To understand the importance of including multiple grade separations, one must consider how the Blue Line extension might have looked if CATS engineers had focused narrowly on delivering fast train run times in the most cost-effective manner possible. For starters, grade separations are expensive compared with standard at-grade crossings, which only require the installation of a flashing gate. CATS could have chosen to construct the line at grade, granting trains travel priority and forcing vehicles to wait throughout the day. This approach would have saved the agency money without sacrificing train run times.
However, while at-grade crossings may save the project sponsor money in the short run, they increase roadway delay and air pollution from idling vehicles traveling within the rail corridor. As a result, the Charlotte region would suffer from reduced economic productivity and more polluted air. Fortunately, NEPA requires project sponsors to take into account how new facilities will affect safety, air quality, and roadway conditions, among other measures of community and environmental impact.
Safety is another core community impact under NEPA. This means that project sponsors must consider how a new facility may increase injuries and fatalities. A portion of the Blue Line will travel along roadways with numerous cross streets that are not signalized, meaning that pedestrian and vehicle movements are not controlled by traffic lights but by stop signs and individuals’ discretion. For roadways with few pedestrians and low traffic volumes, this approach works well. However, the presence of a new light rail line would increase development, travel demand, and pedestrian use. In response, CATS added traffic lights to fully control vehicle and pedestrian movements along U.S. Route 29, Orr Road, Arrowhead Drive, Owen Boulevard, Orchard Trace Lane, and at the University City Station. CATS notes in the environmental impact statement: “With light rail transit running in the median, safety requires traffic signals at all median openings.”
Lastly, NEPA requires project sponsors to look at how a proposed facility will affect low-income communities and communities of color. This mandate stems from a sober and honest recognition that the location, scale, and design of infrastructure facilities have historically affected poor or otherwise disadvantaged neighborhoods at disproportionately high rates.41 In short, the choice to build an infrastructure project can itself be a form of discrimination. This impact may take the form of increased pollution and noise; increased household costs; reduced transportation access; or the loss of local businesses, housing, religious institutions, and social service providers through eminent domain, among other impacts.
As part of the environmental review process, CATS was required to conduct both a demographic analysis based on census data and an extensive inventory of community assets. The Blue Line extension will run through several neighborhoods in which residents are predominantly people of color with incomes that fall substantially below the area’s median household income.
In order to construct the Blue Line, CATS had to acquire 90 acres of land, resulting in the displacement of 14 commercial or industrial businesses but no residential displacement. CATS found that none of the businesses “provide a unique or special service to a community of concern.” Therefore, the project’s most significant impact would be increased noise and vibrations. Eleven residential homes were expected to face a significant increase in noise or vibration. These impacts are considered adverse “due to the intensity of the impacts and disproportionate as no residential noise impacts would occur outside of minority and low-income communities of concern.” In response, CATS made changes to the project design to include the installation of “an automated friction modifier, noise barriers, sound insulation, specially-engineered track work and vibration isolation treatments.”