The “South Sacramento Corridor” — the area east of the Sacramento River and south of the Downtown Sacramento within Sacramento County — is one of the fastest-growing urban areas in the state of California and the nation. According to the U.S. Census, the Sacramento consolidated metropolitan statistical area population grew from 1.5 million to 1.8 million, a 21% increase between 1990 and 2000. With robust employment opportunities in communities, such as the City of Elk Grove, the Census projected this growth in the area to be even faster between 2000 and 2025.
With the county’s existing light-rail system unable to handle this growth and increasing commuter congestion in the California State Highway 99 and Interstate 5 corridors, the Sacramento Regional Transit District (RT), in 1993, began planning the South Sacramento Corridor Light Rail Extension. To address budget constraints and lessen traffic and construction impacts on local citizens, design and construction of the light rail line — also known as the Blue Line — was broken into two phases.
The first phase, a 6.3-mile line from downtown Sacramento south of Broadway to Meadowview Road, was completed in fall 2003 and is currently operational. This year, RT will complete the second phase of the Blue Line. The project, one of the highest priority transit initiatives in the region, will extend light rail 4.3 miles from the existing terminus at Meadowview Road to Cosumnes River College.
“It’s about time,” says Diane Nakano, PE, assistant GM, engineering and construction for RT. “This extension has been more than a decade in the making due to a long environmental review process, funding challenges, design issues and the “Great Recession.” A number of community members still remember the work they did all those years ago on this project. The completion of the Blue Line extension is a testament to their efforts.”
The Blue Line extension will provide thousands of South Sacramento residents comfortable and fast travel every 15 minutes during the week days. Some of the project’s major features include:
• A five-story parking structure at the Cosumnes River College Station that features 2,000 spaces, solar photovoltaic panels and electric-vehicle charging stations. The parking structure opened in June 2013.
• A new eight-berth transit center for bus transfers at the Cosumnes River College Station with flexibility to accommodate articulated buses for future service. The transit center includes custom bus passenger shelters designed to be visually compatible with the other structures of the station.
• Two light-rail bridges, one over Morrison and Union House creeks and Union Pacific tracks and the other over Cosumnes River Boulevard near the college at Bruceville Road and Cosumnes River Boulevard intersection.
• Four new stations at Morrison Creek, Franklin Boulevard, Center Parkway and Cosumnes River College. Each of the four stations feature side platforms, one for boarding inbound trains and the other for boarding outbound trains. The four stations also feature a mini-high platform at the front-end for providing easy access to mobility-impaired passengers, fare vending equipment, drought-resistant landscaping, bicycle racks and lockers, and two electronic message display signs on each platform.
• Pedestrian bridges over Union House Creek near Franklin Boulevard and Center Parkway stations to provide easier access to neighborhoods.
• A multi-use hike-and-bike trail north of Cosumnes River Boulevard and the new light rail tracks.
To successfully complete this $270 million project, RT commissioned Lockwood, Andrews & Newnam Inc., (LAN) a planning, engineering and program management firm, to provide civil and track design and coordinate project delivery. AECOM designed the two light-rail bridges, while MFDB Architects and HLA Group Landscape Architects & Planners Inc. designed the stations, and Systra Consulting provided system design services. Balfour Beatty Rail Inc., Balfour Beatty Infrastructure Inc., and Teichert Joint Venture (BBRI/BBII/Teichert JV) served as contractors with MCM Construction Inc. building the two bridges.
One of the most distinctive aspects of the project is the 2,000-space parking structure built at the Cosumnes River College through a partnership between RT and the Los Rios Community College District (LRCCD), the second largest community college district in California comprising American River, Cosumnes River, Folsom Lake and Sacramento City colleges.
In May 2005, LRCCD met with RT to discuss the possibility of cooperatively providing parking for the project at the Cosumnes River College campus. The meeting resulted in two parking options: 1) acquisition of 10 acres for surface parking devoted to light rail users to be acquired by RT in the vicinity on non-campus property, or 2) construction of a 2,000-space parking structure on campus. RT, in consultation with LRCCD, conducted an assessment of the options, including an environmental review. RT and LRCCD ultimately decided to construct the parking structure with flexible use of the facility and adjoining surface parking for transit riders and students.
“When the project was first initiated, we looked at providing surface parking but that would have taken 10 acres of land that could be better used for other purposes like a high-density residential or mixed-use development,” says Nakano. “We also realized that building this parking structure in partnership would provide a number of benefits for both the college district and the transit agency. Additionally, it helped RT accomplish Federal Transit Administration’s goal of providing livable communities around transit projects.”
Subsequently, in 2011, RT and LRCCD entered into a 50-year leasing agreement with options for two five-year periods. Under the agreement, LRCCD would own, operate and maintain the parking structure while RT paid for the construction costs as prepayment for the lease. The agreement also provided for the transfer of easements to RT for the light rail system, including permanent light rail transit and temporary construction easements.
“RT doesn’t have to pay for on-going operations and maintenance costs, which are usually the biggest expense for a transit agency,” says Nakano. “Also, LRCCD now has two college campuses connected to the light rail system. The existing light rail system is already connected to the Sacramento City College campus. Now, students who may have problems with class availability in one campus can access the other campus in a fast and efficient manner.”
The Blue Line extension presented a number of alignment and operational challenges to the project team. Just south of Meadowview Road, the light rail extension shared a corridor with Union Pacific Railroad (UPRR) for the first three-quarters of a mile. During the first phase of the Blue Line, UPRR’s safety regulations had only required a 20-foot separation between its tracks and the light-rail tracks. As such, RT initially planned to purchase the westerly 40 feet of the UPRR corridor to allow a buffer between light-rail trains and Union Pacific freight trains. Due to derailment issues in other parts of the nation, the railroad changed its safety requirements midway through the project’s design and presented RT with one of two options: Increase the separation from 20 feet to 50 feet or build an $8 million to $10 million barricade between the two sets of tracks. Considering the cost of the barricade wall and the fact that RT still would have required taking a slice of the backyards, the agency chose the first option and purchased another 20 feet of right-of-way from approximately four dozen backyards.
“After acquiring the necessary right-of-way, we had to effectively redesign the track structure and the infrastructure for the signaling system,” says David Clary, PE, LAN’s project manager. “Moving the alignment further complicated the project as there were a number of utility lines running in that area, including Sacramento Municipal Utility District’s overhead power lines. We had to shoehorn the alignment between these lines and also allow access to utilities for inspection and repair work.”
Another challenge involved a 20-inch PG&E natural gas transmission line in the same corridor. Originally, RT had planned to relocate the gas line beneath an adjacent residential street where it would be easier to operate and maintain. However, in the aftermath of a 2010 San Bruno explosion, relocation of the gas line became a real concern for residents on that street. To solve this issue, the project team built an underground concrete retaining wall, approximately one-foot thick and 15 feet deep, to separate the RT light rail track and the PG&E gas line. This also allows PG&E to excavate the pipeline without disrupting the tracks for necessary maintenance.
Noise mitigation was another concern. The east-west part of the alignment passed through a narrow, fixed corridor with residential development to the north and the south. The project team considered constructing sound walls in that section to reduce operating noise but rejected that option.
Instead, the project team decided to attach vibration dampers to the rails in that section. The dampers, which were tested and recommended by acoustic firm ATS Consulting, absorb specific vibration frequencies, thereby reducing the amount of noise radiated by the rail. Combined with a carefully-designed rail grinding program that provides a smoother track surface, the project team observed a total noise reduction of six to eight decibels during testing.
“In the United States, this is the first time vibration dampers have been installed for a light rail project,” says Clary. “By using these dampers, we also eliminated the need for a sound wall in that section which reduced the project costs.”
Despite these challenges, RT is on track to achieve substantial completion of construction in May. System testing and operator training will be performed between May and August with revenue service expected to begin on Sept. 6.
Once completed, the Blue Line extension will improve and expand public transit service in South Sacramento County, enhance regional connectivity, and accommodate future travel demands through interconnected rapid transit options. The project also will alleviate traffic congestion on SR-99 and I-5; reduce auto emissions; improve mobility for corridor residents to employment, education and medical centers; support local economic land use; and transportation goals for the region.
“The light rail expansion comes at a critical time for this city and is a win-win for all the stakeholders,” says Nakano.
Timothy Schmidt is a sr. associate and director, Northern California, at Lockwood, Andrews & Newnam Inc., a planning, engineering and program management firm.