Metro systems are vital circulatory systems for moving large numbers of residents, commuters and tourists around large cities. Metros are mass-transit systems that are generally heavy rail lines that operate on their own rights-of-way, whether underground, at grade or on elevated viaducts. They are distinct from light-rail and commuter rail networks.According to the International Association of Public Transport (UITP), the world's 148 metro systems carry, every day, more than 150 million passengers on 540 lines over 11,000 kilometers to and from 9,000 stations.Since the earliest metro systems were built more than 100 years ago, there have been many advances in
The market is generally healthy and steadily growing, and margins are up for large specialty contractors. Further, advances in design tools and owner demand for collaboration are giving subcontractors a seat at the table early on in projects.