The Express and Rapid Transit Authority of Thailand estimates that commute time now accounts for about one-quarter of the time spent at work with resulting negative effects on business efficiency and productivity. The economic impacts of congestion, when combined with the increasing health impacts from lead-related exhaust pollution, are increasingly showing that Bangkok needs to take specific actions to address its growing traffic problems. There have been many planning efforts within the past 15 years, but so far few implemented coordinated projects.