DENVER The busiest holiday for travel is upon us, and the Colorado Department of Transportation (CDOT) and Denver International Airport are preparing for what could be a record-breaking travel season, but will Mother Nature cooperate?DIA officials said they anticipate more than 844,033 passengers between Friday, November 22, and Monday, December 2. That is a 7.5% increase compared to last year's travel period.Travelers on Friday said they expected long security lines and made sure to arrive at the airport with plenty of time. Kenzo Schwab and Phoebe Knox carpooled to the airport with other friends several hours before their flights."I expected it to be pretty, pretty busy, just because it is around the holiday season. And Thanksgiving is a big holiday for families to come together, so I just thought that it'd be busy," Schwab said.According to DIA, the busiest travel days will be November 22, November 30, and December 1. More than 266,000 passengers are expected to move through TSA security checkpoints, and the airport said December 1 is expected to be the busiest day, with more than 90,000 passengers.If you're planning on traveling during this busy holiday period, you're encouraged to get to the airport two hours before your boarding time, especially during peak times, which are 3 a.m. to 4:30 a.m., 7 a.m. to 9 a.m., and 3 p.m. to 5 p.m. Denver International Airport prepared for start of holiday travel seasonCDOT is warning drivers about increased DUI enforcement during the busy holiday rush. From November 21 to December 4, the Colorado State Patrol (CSP) and 75 local law enforcement agencies will be out in force during a Thanksgiving Heat is On campaign, with sobriety checkpoints and additional law enforcement officers on duty.According to CDOT, between 2020 and 2023, Thanksgiving had the second-highest average of roadway fatalities in Colorado during a holiday period. Additionally, Thanksgiving ranks third-highest for impaired driving-related fatalities during holidays over this same time frame.But the big question is: Will the weather be a factor in slowing things down? The answer is: Significant travel impacts are expected on mountain roads Sunday and Tuesday night through Wednesday.Snow will develop in the mountains on Sunday, and we'll see a chance of light snow across the Denver metro area late Sunday night into Monday morning. Accumulations should remain below 1-2 inches for most of the high valleys, with 2-6 inches for the higher elevations. But a bigger storm is on the horizon.The National Weather Service (NWS) is forecasting a quick system to move in Tuesday evening and out of the state by Thanksgiving, with snowfall exceeding a foot in the high country. According to an NWS forecast discussion, the Interstate 70 Mountain Corridor may see significant travel impacts Tuesday night and Wednesday.The upper-level trough accelerates eastward over Colorado Wednesday. Colder air aloft will help to steepen lapse rates moderately beginning Tuesday night and boost snowfall rates in the high country, with increasing potential for significant travel impacts on most mountain roadways. Storm-total snowfall amounts exceeding 1 foot appear increasingly likely (>80% chance) for the higher mountain elevations, with a possibility of higher amounts if wetter solutions verify, the forecast discussion said.Thanksgiving day should be dry but cold, with a high in the mid-30s for the Denver metro area.DENVER WEATHER LINKS: Hourly forecast | Radars | Traffic | Weather Page | 24/7 Weather Stream Click here to watch the Denver7 live weather stream.