Routes: United at SFO, Frontier, Southwest, Alaska/SAA, AA, Aeromexico, more - Chron

Routes: United at SFO, Frontier, Southwest, Alaska/SAA, AA, Aeromexico, more  ChronIn route news this week, United adds two new destinations from San Francisco, doubles frequencies on an SFO transcontinental route, and eyes a new Europe destination from Newark; Frontier adds a new SFO flight; Southwest adds Bay Area intrastate service; Alaska Airlines partners with South African Airways; American starts new Honduras service and adds domestic markets; Aeromexico boosts its transborder s