In a year unlike any in living memory, at least one seasonal aspect of daily life has recurred this spring, potholes.

But fewer have been noticed this year than last year, likely because of reduced traffic on Boston roads.

Since December 1,639 potholes have been reported to 311, according to Boston Public Works department data.

By this time last year 3,788 had been called in. Despite several storms this winter, pothole reports are down nearly 57%. “It's safe to say that, with so many people working remotely due to the Coronavirus, fewer people were traveling on our streets, leading to a decrease in pothole reporting to 311,” Chris Coakley, public information officer for the Public Works Department (PWD), told The Boston Guardian in an email.

Though traffic has ticked back up in recent months, the number of car trips taken across Massachusetts has been down 20 to 30% for much of this winter, according to data from the Bureau of Transportation Statistics.

But even with the significant drop in tire-damaging craters, the city has failed to meet its goal of addressing 80% of reported holes within one business day.

This winter’s rate has been 60% since January 1.

“The 60% quarterly figure was due to inclement weather and PWD crews focusing on snow and ice control operations,” wrote Coakley. Two years ago, the city’s pothole crews worked faster, filling 74% of holes within one business day. Of this year’s 1,639 reported fissures, 284 have been reported in Back Bay, Beacon Hill, Fenway and the South End neighborhoods. Last year, there were 616 potholes reported in those neighborhoods over the same period.

Potholes happen when water seeps underneath the roadbed and freezes, causing the water to expand. Cycles of freezing and thawing move and disrupt the ground under the road, leading to fissures and holes. After a wet December, an unseasonably dry January was followed by a February with colder weather than most years, according to the National Weather Service.

Despite less precipitation than usual, the year’s shortest month saw severe enough temperature swings to cause fissures in asphalt. It was 11 degrees Fahrenheit on February 12 and 50 degrees 12 days later.

The problem of potholes is exacerbated by cuts that work crews make in roads, which water seeps into. By working with various utility companies and contractors, Coakley said the city’s Utility Coordination System is attempting to synchronize road work to reduce cuts made into newly resurfaced streets. Even with the threat of increased precipitation, flooding and storm surges due to climate change, Coakley said he does not expect the more severe weather to increase the annual spate of holes.