A federal government shutdown is looming, with the government set to run out of funding at midnight from Sept. 30 to Oct. 1.

       Here are some frequently asked questions about the impacts a potential shutdown would have on travel:

       Transportation Security Administration workers at airport checkpoints will continue to work -- without pay -- during a shutdown.

       According to Department of Homeland Security documents, 58,488 employees out of the total TSA workforce of 61,475 will be retained during a shutdown.

       No. Commercial flights will continue to operate and airline employees will not be impacted.

       Over 13,000 air traffic controllers will continue to work -- without pay -- during a shutdown, according to the Department of Transportation's shutdown plan.

       Training for new air traffic controllers will continue at the ATC academy using funds from previous years, according to the DOT's shutdown plan.

       During the 2018-2019 government shutdown, ATC training was stopped. NATCA, the union representing air traffic controllers, previously told ABC News that the shutdown in 2018-2019 "eroded critical layers of safety necessary to support and maintain the [national air space]. Many of the safety activities that proactively reduce risk and increase the safety of the system were suspended during that shutdown."

       During the 2018-2019 shutdown, which lasted for 35 days, TSA officers called out of work at an increased rate due to financial hardship, a TSA spokesperson told ABC News at the time. Those staffing shortages caused some TSA lines to close, which led to an increased wait time for passengers to get through security.

       ABC News reported that air traffic controllers called out sick at the centers in New York, Washington, D.C., and Jacksonville, Florida, leading to a staffing-related ground stop at New York's LaGuardia Airport and flight delays at some New York and Florida airports. Hours after flights were stopped, President Donald Trump ended the shutdown. Sen. Bernie Sanders, I-Vt., credited the controllers with ending the shutdown, The New York Times reported.

       Amtrak said in a statement that its operations will continue as usual.

       "Passengers planning to travel on Amtrak trains in the Northeast Corridor and across the country in the coming days and weeks can be assured that Amtrak will remain open for business," Amtrak said.