• A record number of Americans are expected to hit the roads for the Fourth of July.
  • Low gas prices and a booming economy mean families have plenty of disposable income to invest in summer travel, AAA says.
  • The group, along with the analytics firm Inrix, has calculated estimates for the most crowded places and times.
  • Here’s where traffic is expected to be worst – and the best time to leave to avoid it.

Wednesday, on the eve of the July Fourth holiday, is set to be one of the busiest travel days of the year.

AAA estimates that nearly 49 million Americans will hit the road to celebrate Independence Day, a record-high number that would be a 4.1% increase over last year’s travel volumes.

“In addition to lower gas prices compared with last summer, broader economic fundamentals remain strong,” the group said in a press release. “Low unemployment, robust consumer spending, and rising disposable incomes are all encouraging more consumers to invest their hard-earned money in travel this summer.”

Travelers won’t just be clogging up highways from coast to coast; they’ll also be heading to airports in a similarly record-breaking fashion, with 3.96 million people expected to fly and another 3.55 million expected on trains, buses, and cruise ships.

But while gas is cheap, vacationers will be paying more for airfare, which AAA estimates is up about 10%.

In collaboration with the analytics firm Inrix, AAA has predicted where traffic will be the worst and when you can leave to avoid it.

"With record-level travelers hitting the road this holiday, drivers must be prepared for delays around our major metros," Trevor Reed, the transportation analyst at Inrix, said in a press release. "Although travel times are expected to nominally increase throughout the week, hands down, Wednesday afternoon will be the worst time to be on the road."

Here are the cities with the most anticipated congestion and which times to avoid:


Atlanta

Foto: sourceErik S. Lesser/Getty Images

Worst day for travel: Friday, July 5

Worst time for travel: 5 p.m. to 7 p.m.

Delay multiplier: 2.5 times


Boston

Foto: sourceAP/Elise Amendola

Worst day for travel: Friday, July 5

Worst time for travel: 10 a.m. to noon

Delay multiplier: 3.4 times


Chicago

Foto: sourceCharles Rex Arbogast/AP

Worst day for travel: Friday, July 5

Worst time for travel: 1 p.m. to 3 p.m.

Delay multiplier: 2 times


Detroit

Foto: sourceReuters/Peter Nicholls

Worst day for travel: Wednesday, July 3

Worst time for travel: 2 p.m. to 4 p.m.

Delay multiplier: 2 times


Houston

Foto: sourceStan Honda/Getty Images

Worst day for travel: Thursday, July 4

Worst time for travel: 1 p.m. to 3 p.m.

Delay multiplier: 3 times


Los Angeles

Foto: sourceKABC-TV/AP

Worst day for travel: Wednesday, July 3

Worst time for travel: 11:30 a.m. to 1:30 p.m.

Delay multiplier: 2.7 times


New York

Foto: sourceDrew Angerer/Getty Images

Worst day for travel: Wednesday, July 3

Worst time for travel: 1:45 p.m. to 3:45 p.m.

Delay multiplier: 3.8 times


San Francisco

Foto: sourceWonderlane/Flickr

Worst day for travel: Wednesday, July 3

Worst time for travel: Noon to 2 p.m.

Delay multiplier: 2.5 times


Seattle

Foto: sourceElaine Thompson/AP

Worst day for travel: Thursday, July 4

Worst time for travel: Noon to 2 p.m.

Delay multiplier: 3 times


Washington, DC

Foto: sourceAP/Jacquelyn Martin, File

Worst day for travel: Sunday, July 7

Worst time for travel: 10:30 a.m. to 12:30 p.m.

Delay multiplier: 2.4 times