Usually it takes the news media's spotlight on a serious injury or accident to get government bureaucracy to do their jobs. Also the reality of a potential costly personal injury lawsuit serves as a motivation for municipalities to take steps to reduce the possibility of injuries to its citizens.
Los Angeles's transit agency, the MTA is in the process of installing safety barriers on all light rail platforms to prevent people from accidentally walking between train cars. Last year the MTA purchased new rail cars that had gaps between the cars. At the time, the Federal Transit Administration, as part of its safety certification, raised concerns about the spaces between the cars.