OMAHA, Neb. (AP) — The major freight railroads have announced a number of steps they are taking to improve safety in the wake of last month’s fiery Ohio derailment. It’s not clear, however, that the actions they announced Wednesday will be enough to satisfy regulators and members of Congress who are pushing for changes. Many of the proposals from the Association of American Railroads trade group focus on strengthening the network of trackside detectors the railroads use to spot problems before they can cause derailments. The group proposes installing roughly 1,000 more of them nationwide and tweaking the way railroads use the data from them.