Damaged pipelines are 'ticking time bomb'
Updated 1945 GMT (0345 HKT) May 31, 2016
Chat with us in Facebook Messenger. Find out what's happening in the world as it unfolds.
Washington (CNN)Nearly 40 million Americans will kick off one of the busiest travel seasons in history this Memorial Day weekend, jarred by potholes on America's roads, crossing her aging bridges, riding her antiquated railways and taking off from airports that draw international scorn.