In response to the dramatic growth of Panama City in recent years—along with severe traffic congestion—a design-build team is constructing a 14-kilometer, $1.8-billion light-rail line that will be the first of its kind in Central America. The $1.8-billion Panama Metro project features two earth-pressure-balanced tunnel-boring machines, each 9.77 meters in diameter.

One machine, dubbed "Marta," began work in February and will excavate four kilometers of the southern part of the route. The other TBM, "Carolina," started in April and will do just more than three kilometers of the northern section. Both will be removed at the Iglesia del Carmen Station, which is being prepared for their arrival next spring.

The government launched the Panama Metro project at the end of 2010, with a completion date set for 2014. “We are going to transform the former transportation chaos in Panama into a safe, reliable system for all citizens,” Panama President Ricardo Martinelli stated at the announcement of the tender for the project last October.

When Martinelli was elected Panama’s president in 2009, modernizing the public transport network in Panama was one of his key priorities. He put the metro project on the fast track, ordering the creation of the Panama Metro Secretariat, the governmental agency in charge of building and running the train line. 

The approximately $1.45-billion contract was awarded to a consortium, Línea Uno, that includes Brazil's Norberto Odebrecht and Spanish company Fomento de Construcciones y Contratas (FCC). Alstom will provide the 19 three-car train sets as well as electro-mechanical equipment on a turnkey basis.

The Panama Metro route includes seven kilometers of tunnels and more than five kilometers of elevated guideway. It will connect the transportation and shopping hub of Allbrook on the city’s south side to residential areas northeast of the urban center. 

The higher costs associated with excavating the underground route was offset by the savings from constructing the train line across Panama City's densely populated center. It alleviated the need to purchase additional land and make right-of-way agreements with existing landowners.

“By going above and below the existing roads, we avoid a lot of the expense of securing the right-of-way,” explained Augustin Arias, the chief engineering adviser for Panama Metro. “About 85% of the route follows existing roads.” Still, the government had to reclaim several parking areas on the existing right-of-way.

The TBMs proved to be a more-cost effective approach than the drill-and-blast method due to the reduction in cost of lining the tunnel, Arias explained.

To build the subterranean stations, crews place precast-concrete wall sections into the earth and then excavate the material within. Once this is completed, the internal structures are built. Station platforms are approximately 100 meters in length.

The elevated sections will require the construction of 175 support structures along 5.12 kilometers. The 10-m-wide workspace abuts the existing roadways.

When completed, a complete trip through all 13 stations of the route will take less than 23 minutes. Now, that same journey in a regular vehicle at peak traffic times can take more than an hour. More than 700,000 vehicles travel the city’s roadways each day.

At startup, the Panama Metro will be able to handle a peak of 15,000 passengers per hour in each direction. With the phasing in of additional trains, that number is slated to increase to 40,000 passengers an hour and approximately 700,000 each day.

Line 1 is the first of a total of four metro lines proposed to be built by 2035. Feasibility studies for a second section are expected to be completed in 2014, and the government of Panama hopes to put the work on that portion up for bid by the end of that year.

Almost half of Panama’s 3.5 million residents live in Panama City. While the global economic downturn tempered the country’s economic expansion for several years, it has since seen a return to double-digit growth.

Along with the metro project, the governments of Panama and Panama City have ramped up investment in the city’s road infrastructure, phased in a city-run bus system to replace the chaotic system of private services and are upgrading 16 key intersections.