"Skanska is currently working on three major transit projects in New York: the Second Avenue subway, the 7-line extension and the Fulton Street transit center. On phase one of the Second Avenue subway, beginning in 2007, we made a big, open cut, excavated down 100 ft and launched two tunnel-boring machines. Later, we mined out a cavern for a new station with rock-blasting. We are completing it this fall," reports Cobelli.

In Los Angeles, Skanska is joint-venturing on phase two of the Expo line in Santa Monica and is the apparent low bidder on the West Side subway. "In partnership with Traylor Bros., we were recently awarded the regional connector project, a billion-dollar job," says Cobelli. "Los Angeles has a great program to fund transit projects. Measure R is projected to raise $20 billion over 30 years. We are in [the fifth] year. Measure R2 is coming up in 2016, which would make the sales tax permanent so it will raise dollars beyond 2030."

Denver is another city making great strides in transit. "Balfour Beatty is in a joint venture on Eagle P3, a design-build-finance-operate-maintain project to implement a brand-new commuter rail system, with 35 route miles along three grade-separated corridors," says Roger Wilson, vice president of Balfour Beatty Rail Transit. The $2.7-billion job was awarded in 2010 and opens in 2016.

China is outstripping all other countries in its commitment to metro transit. Of its 22 operating metro systems, 17 have opened since 2000. Fourteen more are currently under construction and expected to open by 2020. China’s cities are often larger and denser than their Western counterparts; of the cities planning to build metros, all have more than a million people in their metropolitan areas and most have more than three million.

The Moscow Metro is undergoing a tremendous expansion. Between 2012 and 2020, it expects to add 150 kilometers of new routes and 70 new stations, including a second circle line.

In March 2014, Lima awarded a contract to build and operate Line 2, a 35-km underground transit line. Consorcio Nuevo Metro de Lima, the winning bidder, is made up of four firms: ACS and Fomento de Construcciones y Contratas, both Spanish firms, and Salini Costruttori and Finmeccanica, both from Italy. Of the $5.7-billion investment, the government will cover $3.7 billion for the construction and trains and spend $490 million on expropriating property, while the consortium will contribute $1.47 billion. Lima has a population of 7.6 million.

Salvador, Brazil, a city of 2.6 million, selected a public-private partnership, CCR (Companhia de Concessões Rodoviárias) Metrô Bahia, to build and operate Line 2 of its metro system, for $1.85 billion. The 24.2-km line will have 13 stations. CCR is a consortium of Spanish companies Construcciones y Auxilar de Ferrocarriles (CAF), ICF and Dimetronic.

One of the most ambitious metro construction undertakings in the world is taking place in Saudi Arabia. In July 2013, the government launched a $23.5-billion plan to build Riyadh's first metro rail system, awarding contracts for the system to three foreign-led consortia. Six rail lines carrying electric, driverless trains and extending 176 km are to be completed by 2019. Riyadh currently has 5.3 million residents; however, given Saudi Arabia's rapid population growth rate, the city is projected to have eight million residents by 2030.

Lines 1 and 2 in Riyadh have been awarded to the BACS consortium, led by Bechtel and including Siemens and Almabani General Contractors. Line 3 is being executed by ArRiyadh New Mobility, a consortium comprising two groups: the Civil Work Group of Salini-Impregilo, which includes Larsen & Toubro and Nesma; and the Electrical Work Group, which includes Ansaldo STS and Bombardier Transportation. Lines 4, 5 and 6 will be built by the FAST consortium, led by FCC and including Samsung C&T, Alstom, Strukton, Freyssinet Saudi Arabia, Typsa and Setec.

Kolkata, India, which opened its first metro line in 1984, currently is building four additional lines. Line 2, which has progressed the farthest, will begin operating its initial 9-km-long first section in September 2015. It is being built by Consolidated Construction Consortium and Sam Infrastructure.

Toronto is extending its Spadina subway line an additional 8.6 km. The $2.4-billion project started construction in 2009 and is scheduled to be completed in 2016.