The widely dreaded first day of intensive track repairs at Pennsylvania Station in Manhattan was far less hellish than forecast, but New York City’s hardened commuters were reluctant on Monday to exhale in relief too soon.

Many of them were still figuratively holding their breath as they trudged homeward in the evening, in some cases forced to try out different routes than the ones they had taken in the morning. After a series of train derailments in the past few months, they all knew a devilish disruption could occur at any moment.

“This has been the best commuting day of my life so far,” Barbara Strautman, 58, said as she waited for a Long Island Rail Road train home to Port Washington. She had started out just 10 minutes earlier than usual in the morning, and all had gone smoothly.

Still, she said, “everybody is very wary; this is only Day 1.”

She was referring to the first of 44 days of reduced train service at Penn Station, the busiest train station in the country. The three railroads that use the station — the Long Island Rail Road, New Jersey Transit and Amtrak — have all cut back their schedules, canceling some trains and rerouting others, to accommodate emergency work on the station’s tracks.