Travelers flying through San Francisco are facing hundreds of delays and cancellations because of runway construction

San Francisco International Airport (SFO) has closed one of its four runways for crucial repairs from September 7 to 26.
Although airlines reduced their schedules to SFO for the period, the reduced runway capacity has led to major delays and cancellations since they began this past Saturday.
Hundreds of travelers were stranded over the weekend, and cascading delays look likely to continue through the entire repair project.
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When San Francisco International Airport announced in March that it would close one of its runways this month for crucial repairs, airlines worked to plan ahead by reducing flight schedules and offering different connection options for passengers.

But as the runway ceased operations on Saturday, it quickly became clear that those steps were not enough. Over the weekend, the airport became a "massive mess," according to a San Francisco Chronicle report.

San Francisco Airport (SFO) is the seventh-busiest airport in the US, according to data from the FAA, moving more than 53 million passengers in 2016.

As hundreds of travelers faced delayed and cancelled flights over the weekend and Monday, some wondered whether the flight reductions a 13% decrease was enough, and what more could have been done.

More than 800 flights were delayed between Saturday morning and Monday afternoon, according to data from flight-tracking website FlightAware cited by the Chronicle, with delays averaging an hour. On Tuesday morning, around 85 flights to or from SFO had been cancelled, with another 80 delayed the number was likely to increase throughout the day. According to FlightAware, inbound flights were delayed an average of about three-and-a-half hours.

Passengers were left unprepared for the delays, leading many to complain to their airlines on Twitter.

"Hey @AmericanAir, would have been nice to know when purchasing tickets to SFO that runways were set to be closed," one passenger tweeted. "Beyond frustrated right now. 3+ hour delays."

"@AlaskaAir 5 hour delay on our 2 hour Seattle to SFO flight due to a PLANNED construction," another user asked . "What part of this was a surprise? Will the flight take off tonight at all?"

SFO has four runways: two running parallel to each other (10L/28R, and 10R/28L), and another two runways going perpendicular (1L/19R, and 1R/19L), crossing the first two runways.

The issue is that that in 2017, engineers saw that a 1,900 foot strip of runway 28L was in desperate need of repairs, with pavement in the concrete base layer deteriorating. However, that strip of affected concrete is crossed br the two perpendicular runways 1L and 1R. That means that repair work isn't as simple as closing one runway and using the others. Take-offs and landings instead need to be coordinated around when crews will be working on the intersecting portions.

The airport said that it waited until September because it needed dry weather to complete the repairs, and the busy summer travel season made July or August an impractical time to close a runway.

Most major US airlines are letting passengers scheduled to fly to or from SFO to change their flights if they want to contact your airline for more details.

The repairs are expected to continue from September 726, with the runway reopening the morning of September 27.

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