Cities around the world are taking a fresh look at monorails, hoping that the single-track elevated systems can provide urban mobility solutions at the right price. The Wall Street Journal writes that an 18-station line has been operating in Chongqing (China) for six years, and new systems are under construction in Mumbai (India), Riyadh (Saudi Arabia), Daegu (South Korea), and São Paulo (Brazil). While skeptics acknowledge that monorails can work in environments like theme parks and airports, they question the effectiveness of the technology in urban mass transit settings. Other perceived obstacles include questions about the impact of elevated structures on urban landscapes and concerns about evacuating stranded passengers from disabled trains. Still, cost may be the deciding factor for many locales, as a monorail can be constructed for substantially less than a subway. Link to full story in Wall Street Journal.