Flying Within the US: Fares, Bags, Security and When to Just Drive

America’s sheer size makes flying the default for long trips: New York to Los Angeles is about 2,800 miles, roughly six hours in the air and a two-day drive. Yet US domestic aviation has its own dialect of fare buckets, bag fees and security rules that regularly surprises visitors from countries where one ticket means one bag and one seat. Here is what to check before you book, what happens at the airport, and when renting a car is the smarter move.

When Flying Beats Driving

Run the door-to-door math, not the timetable math. A one-hour flight consumes about four hours of your day once you add the trip to the airport, arriving early, security, boarding, deplaning and baggage claim. A car drives door to door at an honest average of 55-60 miles per hour including stops. That is why the break-even point sits around 350-450 miles, or five to seven hours of driving.

Trip length	Practical answer
Under 200 miles (under 3.5 hours driving)	Drive, or take a train or bus; flying is slower door to door
200-400 miles (3.5-6.5 hours)	Toss-up; compare total price and schedule (New York to Washington DC is faster by train than by plane)
450-500 miles (7+ hours)	Usually fly; Los Angeles to San Francisco is a 6-hour drive but a 90-minute flight
Over 1,000 miles	Fly; a Chicago to Orlando drive eats two days each way

Cost is the second variable. Fuel for a typical car runs roughly $10-15 per 100 miles at recent pump prices, so a 1,000-mile drive costs about $100-150 in petrol plus motels, which is why three or four people sharing a car often beat three or four airfares. The math flips for solo travelers and for one-way trips, where rental companies charge a drop fee for returning the car somewhere else (see our car rental guide). Before you lock in either option, price the full trip, not the fare: use our Real Price Calculator and compare drive cost against airfare plus bags plus the rental car you will need at the far end anyway.

Who You Will Fly: The US Airline Landscape

Four carriers dominate US skies. The “Big Three” network airlines fly hub-and-spoke: American (hub at Dallas-Fort Worth), Delta (Atlanta) and United (Chicago, Denver, Houston, Newark, San Francisco). Ranked by 2025 capacity, United was the largest US carrier, followed by American, Delta and then Southwest. On smaller routes you will often fly regional partners (United Express, Delta Connection, American Eagle) operating 50-76 seat jets.

Southwest Airlines deserves a separate word because guidebooks have not caught up: the all-737, point-to-point carrier ended its famous free-checked-bags policy on May 28, 2025, and is rolling out assigned seating during 2026, so its two historical perks are gone or going.

On the West Coast, Alaska Airlines is the major carrier; JetBlue is strong on East Coast and transcontinental routes. The budget segment shrank in 2026: Spirit Airlines, the largest ultra-low-cost carrier, ceased operations on May 2, 2026, and its routes were partially absorbed by rivals. If a blog post or aggregation site still recommends Spirit, it is out of date; the remaining low-cost names are Frontier, Allegiant, Breeze and Sun Country.

For a first visit, book the Big Three or Southwest for schedule depth and rebooking options. The action is simple: compare on Google Flights or the airline’s own site, pick the nonstop that fits, and read the fare rules at checkout before you pay.

Basic Economy: The Cheapest Fare Has Teeth

The lowest price you see on the Big Three’s sites is usually Basic Economy (Delta renamed its version “Delta Main Basic” in 2025), a deliberately stripped-down fare built to compete with budget airlines. The restrictions are where the real cost hides:

1. No advance seat selection. You are assigned a seat at check-in, families get split, and buying a seat assignment often costs close to the fare difference itself.
2. You board last. American, for example, puts Basic Economy passengers in the final boarding group, by which point overhead bin space is gone.
3. Carry-on restrictions. United’s domestic Basic Economy is the strictest in the market: a personal item that fits under the seat, no full-size carry-on, and a gate-checked bag (and fee) if you show up with one anyway.
4. No changes, no refunds, reduced miles. The ticket is effectively frozen the moment you buy it.

Airline	Carry-on on the basic fare	Seat selection	Boarding
American	Included	Paid only	Final boarding group
Delta (Main Basic)	Included	Paid only, assigned at check-in	Last zones
United	Personal item only on domestic routes	Paid only	Last group
Southwest	Included (checked bags now cost extra)	Assigned seating rolling out in 2026	Check fare rules at booking

The practical rule: at checkout, open the fare comparison and price standard economy against Basic Economy plus the seat and bag you will actually buy. If the gap is under about $40-60, buy regular economy and stop thinking about it. These rules change often, so read the baggage and seat lines for your specific flight before you pay, as of October 2026.

Bags: What They Cost and What Goes Where

US carriers now charge for checked bags across the board, so budget for luggage as part of the fare:

• First checked bag: roughly $30-40 each way on the major airlines, more for a second bag, and often a few dollars extra if you pay at the airport counter instead of online. These are conservative figures that vary by airline and route; check your carrier’s fee page before booking.
• Southwest included its trademark two free checked bags until May 28, 2025; bookings since then pay standard bag fees like everyone else, so ignore older advice that says otherwise.
• Carry-on: one full-size roller up to about 22 x 14 x 9 inches (56 x 36 x 23 cm) plus one personal item, standard across the Big Three. Airlines put sizers at the gate and charge for gate-checking oversize bags.
• Weight: 50 pounds (23 kg) per checked bag before overweight fees jump sharply. Weigh your bag at the hotel; bathroom-scale tricks work.
• Liquids over 3.4 oz (100 ml) must travel in a checked bag, so full-size sunscreen and toiletries push you toward checking a bag on the way home.

Pre-pay bags online when you check in, keep the receipt, and add the fee into your real trip cost, not after the fact. Two people checking one bag each on a round trip are looking at $120-160 in luggage fees, which is often the difference between fare classes.

Security, Liquids and Your Passport

Everyone 18 and older shows photo ID at the federal security checkpoint, and the accepted list is friendlier to visitors than most people expect: a foreign government-issued passport is a valid ID for domestic US flights, full stop. Canadian provincial driver’s licenses are accepted too. Keep your passport in your carry-on, never in checked luggage.

You do not need a REAL ID. REAL ID is a US federal standard for state-issued driver’s licenses, created by the REAL ID Act of 2005 on the 9/11 Commission’s recommendation, with enforcement starting May 7, 2025. Since that date, Americans whose licenses are not REAL ID-compliant cannot use them at checkpoints. None of that applies to you: a passport works in place of a REAL ID for anyone, and your passport is not a US state license, so the rule never touches visitors. Travelers who show up with no acceptable ID face additional identity verification and a $45 fee, so do not test it.

The liquids rule (known as 3-1-1) is the other checkpoint gatekeeper:

1. Containers of liquids, gels, creams and pastes must be 3.4 ounces (100 ml) or less.
2. All of them fit in one quart-sized clear bag per person, placed separately in the screening bin.
3. Medications and infant nourishment are exempt from the size limit; duty-free liquids in sealed, tamper-evident bags are allowed on international connections into the US with the receipt.

The routine at a standard lane: shoes, belt and light jacket off, laptop and liquids bag in a bin. TSA PreCheck lanes (for enrolled frequent travelers) skip most of that; short-stay visitors generally skip enrolling. The official TSA guidance is simply to arrive early and allow time for every step, and you can check posted checkpoint wait times for your airport on tsa.gov or the free MyTSA app before you leave the hotel.

How Early to Arrive, and Connections

• Two hours before domestic departures is the working rule at large airports; 90 minutes is realistic at small airports with one security lane.
• Add time at peak moments: Monday mornings, Friday afternoons, school holidays, and any airport you have never seen before.
• Bag drop closes earlier than the gate: most airlines stop accepting checked bags about 45 minutes before a domestic departure, and jet doors close around 15 minutes out. With a bag to check, arrive before the cutoff, not after.
• Book connections of at least 90 minutes, and two hours at mega-hubs like Atlanta, Dallas-Fort Worth or Denver. If you connect from an international flight, you clear customs and immigration at your first US stop and recheck your bags (see our entry guide), which consumes another hour easily.

Common Mistakes

• Booking Basic Economy without reading the carry-on line. United’s domestic basic fare excludes the overhead bag; travelers discover this at the gate, with a fee attached. Read the fare rules before paying.
• Assuming Southwest bags still fly free. That ended May 28, 2025. Older guidebooks and forum posts have not caught up.
• Bringing full-size toiletries in carry-on. Anything over 100 ml gets confiscated at the checkpoint. Put them in your checked bag before you leave.
• Cutting the arrival window to 45 minutes. Checked-bag cutoffs, security lines and long walks to remote gates eat that margin completely.
• Booking a connection under an hour. A 40-minute connection works until the first flight lands late; then your day is gone.
• Flying sub-300-mile hops. By the time you board and deplane, the train or car would have won. Check driving times before defaulting to a flight.
• Chasing Spirit Airlines fares from old recommendations. The airline shut down on May 2, 2026; any site still selling its tickets is a scam or stale cache.
• Leaving the passport in a checked bag or the hotel. You need photo ID for every checkpoint, every flight, at every age over 17.