Routes: Airlines plan more service resumptions for SFO this summer

As coronavirus-related restrictions continue to ease, airlines are moving cautiously into their summer schedules with a touch of optimism about rising levels of passenger demand for both domestic and international flights. More overseas routes are coming back to San Francisco International in June and July, while United and American are scheduling an expansion of international service from all their hubs. Those two carriers are also expecting to expand domestic operations in July. Meanwhile, American pulls out of Oakland, offers double miles and reopens some Admirals Clubs; Delta extends its seat-blocking policy into September; and Frontier starts temperature checks.