Nightmarish backups. Groans of frustration. Ghastly, grinding commutes.

State transportation officials warned of horrific traffic conditions on Halloween morning, but the dire predictions never materialized.

Instead, drivers sailed into Boston on the Massachusetts Turnpike like it was a holiday, a pleasant surprise to those who expected far worse on the first weekday commute since all-electronic tolling began Friday.

Thomas Tinlin, the state’s highway administrator, said that the first morning “went really well,’’ crediting months of planning and coordination for the smooth ride.

“But the real credit goes to the traveling public,’’ Tinlin said at a Monday news conference, referring to the legions of drivers who adjusted their commutes in anticipation of delays.

Compared with last Monday, about 6 to 10 percent fewer drivers headed east on the Pike through the Weston and Allston-Brighton tolls, officials estimated. That, along with well-designed traffic patterns, allowed drivers to breeze through construction areas at the toll plazas, despite lane closures.

The state is tearing down toll plazas along the Turnpike to make way for 16 all-electronic tolling gantries, which will eventually allow drivers to pay their tolls while maintaining highway speed. But while construction crews are removing the toll booths, drivers will have to funnel into fewer lanes, especially for the next three weeks.

Drivers apparently took heed of warnings from transportation officials, who said the project could cause gridlock. But Tinlin said Monday’s peaceful commute will continue only if drivers continue to avoid the Turnpike. “If people go back to their regular way of travel,’’ he said, “tomorrow could be much different.’’

Peter Furth, a professor of civil engineering at Northeastern University and a transit specialist, said drivers should breathe easy, predicting that traffic won’t be much worse than usual. State officials had overstated the impact of construction from the start, he said.

“I don’t expect it to be as bad as what they predict,’’ he said. “I don’t think that the toll plaza construction is going to make a big difference.’’

Warning of lengthy delays, state transportation officials have urged drivers to use public transit or take advantage of flexible work schedules this week. On Monday at least, the messages worked.

The first phase of construction is expected to last until Nov. 22. By year’s end, all toll booths and related buildings should be gone.

There are currently 23 construction sites on the Turnpike, and officials have reported that work is ahead of schedule in some locations.

On Monday, several toll booths had already been removed on the Allston-Brighton and Weston interchanges, which are expected to see some of the worst traffic. Officials said 76 of 155 tollbooths along the Pike are gone or are in the process of being demolished. In the construction zones, police officers kept watch as signs advised drivers to proceed at 15 miles per hour.

State Police reported just one minor crash in a work zone over the weekend, compared with two on the same days last year and 10 from two years ago.

Steve Collins, the state’s director of tolling, said the system had logged 2.8 million transactions from Friday night to early Monday morning. About 77 percent of the drivers had E-Z-Pass transponders, which give commuters discounted rates.

Officials are urging all drivers to use transponders, and those who do not have them will be charged through the mail after the gantries take a photo of their license plates.

Officials recently announced a six-month grace period to give drivers time to sign up for E-Z Pass. Drivers will be originally charged the higher rate by mail, but can get their accounts credited once they sign up for the electronic passes.

Globe correspondents Dylan McGuinness and Martha Schick contributed to this report. Nicole Dungca can be reached at nicole.dungca@ globe.com. Follow her on Twitter @ndungca.