Copyright CBS News

At the Los Angeles International Airport, the shutdown isn't just causing delays today; travel experts say it could turn the upcoming holiday rush into a nightmare. Air traffic control staffing shortages are already slowing arrivals into LA and if this continues, Thanksgiving could be one of the most disrupted travel weeks the airport has experienced in years. Travelers on Tuesday morning are coming prepared. One woman told CBS LA she arrived at 5 a.m. for her 8 a.m. domestic flight. "I came in extra early because of the shortage. I made sure I got here on time so I could wait through the lines and I'm just like, please don't have any delays," said Tracy Taylor. Air traffic controllers, who are required to work without pay, are calling out in higher numbers. The Federal Aviation Administration (FAA) said at least eight control facilities are short-staffed, delaying flights into cities including Austin, Dallas and Southern California. On Sunday, delays averaged over an hour at both LAX and San Diego. FAA operations plans show nearly 100 staffing triggers over the weekend, the worst since the shutdown started. Holiday travel pressure is building. The U.S. Travel Association warns Thanksgiving could melt down if the government doesn't reopen soon, costing the travel economy up to $4 billion. Last year, 20 million passengers flew Thanksgiving week and this year's demand is expected to be just as strong, even as 60% of Americans said they're now rethinking their plans. Transportation Secretary Sean Duffy was on "Face the Nation with Margaret Brennan" on Sunday, where he said he thinks the delays are only "going to get worse." Airlines at LAX are bracing for record crowds and officials said that if staffing doesn't improve, travelers can expect longer lines, rolling delays and more last-minute cancellations as the holidays get closer. For now, travelers are being told to arrive early, check flight status frequently and hope the shutdown ends soon.