The number of pedestrians killed on U.S. roads declined by 4% in the first half of last year, according to preliminary estimates published Tuesday by the Governors Highway Safety Association.But pedestrian fatality numbers are still far above their 2019 levels."While we've made some modest progress, there's still obviously quite a bit of work to be done," said Russ Martin, the GHSA's senior director of policy and government relations. "We're sti…