SAN FRANCISCO (KRON) – More than 300 delayed flights make for another frustrating day at San Francisco International Airport. 

Tuesday marks day four of a 20-day construction project on one of the airports major runways. 

The main question passengers were asking is how long have airlines known about this construction?

According to airport officials, airlines were notified about this six months ago.

Several of the airlines did cancel flights ahead of time in preparation for this but as the days go on, more and more flights are needing to be either canceled or delayed significantly. 

Passengers feel they weren’t properly notified. 

308 delays and more than 100 cancellations filled the boards at SFO Tuesday. 

Travelers say they did what they could, to get where they needed to go

“The message came across that our flight was delayed, we have the Delta app so it gave me the option to change flights. So I got on a different flight that left the same time our flight was supposed to leave and got here on that one, however, our bags didn’t,” Rich said.

Flights like Rich’s that are arriving at SFO are seeing the biggest issues. 

That’s because runway 2-8-Left, a main runway for landing aircrafts, is undergoing construction through the end of the month. 

“Although this project is primarily happening on that runway, the work is happening where it intersects with other runways so at any given point during this project there’s gonna be two runways at our airport that are shut down,” Doug Yakel, SFO spokesperson, said.

SFO says they alerted airlines back in March about the planned construction.

They chose September because it wouldn’t disrupt busy summer travel but even with notifications on their website and social media posts, some passengers feel they got the message a little too late.

SFO is advising travelers that if they’re flexible, contact your airline and change to another Bay Area airport altogether.

United is waiving change fees and Delta announced they’d be doing the same.

The next few days are going to be the big test, SFO says Wednesday’s through Friday’s are their busiest days.