Photo by Tudor Van Hampton Chicagos $1-billion Red Line rehab falls on the heels of a $530-million modernization of its Brown Line, which wrapped up in 2009. The Red Line is one of the busiest transit routes in the U.S. A $1-billion program to modernize Chicago Transit Authority's Red Line—the backbone of the city's century-old urban rail and one of the busiest routes in the U.S.—is about to get under way.The long-overdue project will rehab Chicago's most traveled passenger rail, which serves 240,000 daily riders. The train stations are outmoded, and track deterioration has prompted slow zones that bog down
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.