Air travelers will likely endure delays at San Francisco International Airport in spring and summer because of construction work on some runways.
SFO will close two of its four runways from mid-May through September.
Construction crews will be installing collapsible pavement meant to stop runaway planes from careening off the tarmac.
The updates are part of a Federal Aviation Administration safety mandate.
During the work SFO will shut down its shorter runways which usually handle departing flights.
Doug Yakel, an airport spokesman, says the runway closures could lead to delays during peak hours on weekdays.
Arriving flights will likely be most affected, leading to more circling over the Bay Area while pilots wait for clearance to land.