Marsha Epstein has been traveling from one end of the state to the other on the Massachusetts Turnpike since 1966, but she’s never seen a traffic jam like the 45-mile backup on Friday night.
“It was unbelievable,” said Epstein, 64, of Newton. She and her husband set off for Philadelphia to visit their grandson at around 3:30 — plenty of time, they thought, to beat the traffic. Instead, they found themselves sitting in gridlock for 2½ hours before they even reached their exit toward New York. “It’s amazing our marriage was still intact,” she said with a laugh.
The Epsteins were among thousands of travelers headed west for the holiday weekend who experienced massive delays in what is believed to be one of the worst traffic jams on the Pike in years.
From midday until about 9 p.m., cars were backed up from Boston to Charlton, from Exit 19 to Exit 9.
Officials won’t know whether it was the worst traffic jam the state has ever seen until tolls are calculated this week.
Last year, according to state Department of Transportation spokeswoman Sara Lavoie, the Friday before Columbus Day weekend was the heaviest travel day of the year, with 363,607 toll transactions between Weston and the New York line. This year, State Police said that it was one of the heaviest travel days they had ever seen.
Officials with the MassDOT are still not sure exactly what caused Friday’s backup, but they have a few theories — starting with the fall foliage.
Western Massachusetts, said Frank DePaola, administrator for the MassDOT Highway Division, is the place to be on Columbus Day weekend.
Unlike Thanksgiving, another travel-heavy day when people are headed in every direction to visit family, on Columbus Day weekend, city dwellers are drawn in just one direction: to the flaming reds and oranges of the Berkshires, upstate New York, and Vermont.
“There’s rivers, there’s tubing . . . apple picking, and all those family-related activities,” said DePaola. The leaves are changing, the weather’s fine.
And how do all these city folk find their way to the country? Global positioning systems.
“The GPS just tells you to take the interstate,” said DePaola. “People are blindly following those devices.”
And the percentage of drivers who use E-ZPasses, which make traveling through tolls faster, usually drops on a long holiday weekend.
On an average traffic day, said DePaola, 70 percent of drivers use the E-ZPasses, and about 30 percent use cash. But E-ZPasses are generally used by travelers who frequently drive long distances on toll roads, he said. On a holiday weekend like Columbus Day, everybody is out on the roads — which means more people scrambling for cash in center consoles and purses.
”It just slows down,” he said. “You have all these people that are backing things up, and that hesitation causes delay. What we need to do is get fewer people stopping along key points in the road.”
And once they actually make it to the tollbooths, not even the travelers with E-ZPasses, he said, are spared.
“Even though we have E-ZPass, we still need to require people to drive through the pass slowly,” he said. “It’s designed for slow collection.”
In New Hampshire, he said, drivers can sail on through at 65 m.p.h., wind in their hair and tollbooth quickly at their back. Not in Massachusetts.
“We don’t have the road width to do that yet,” DePaola said. “It would take tens of millions of dollars.”
Now, officials are looking ahead to Thanksgiving, hoping to prevent another backup like Friday’s.
An “after-action review” is planned for the coming week, said DePaola. Officials will crunch numbers from toll exchanges and see if there is anything they can tweak to make Thanksgiving a little smoother.
For weary travelers concerned about the return trip, there is good news. Extreme backup is not expected for Monday, said Lavoie.
“With the long holiday weekend, people tend to escape,” she said. “They usually come back staggered. I doubt [the traffic] will be as severe as Friday.”
The Epsteins aren’t taking any chances. They will leave Philadelphia early Monday morning, said Marsha Epstein. She and her husband can’t handle another drive like Friday’s.
“We were the very unhappy travelers,” she said.Derek Anderson contributed to this report. Evan Allen can be reached at evan.allen
@globe.com. Katherine Landergan can be reached at email@example.com.