Metro continues to overhaul its track inspection department one year after a high-profile derailment on the Silver Line, but efforts to improve the quality of inspections have been hampered by some seemingly in­trac­table problems: troublesome technology, daily time constraints and the agency’s self-imposed safety regulations that have made it more difficult for inspectors to access the tracks.

An internal report prepared by Metro’s quality control unit — and delivered to senior managers in June — outlined many of these problems, detailing four “wins” within the track inspection department and 14 other “areas for improvement.”

The improvements, according to the quality control unit: Track inspectors have gone through an enhanced training program (“very effective and informative,” commented one of the report’s authors after watching a training session), and more inspections take place at night, when there are fewer interruptions from passing trains. Additionally, workers have finally ramped up their use of an $8 million track inspection machine that was rarely utilized before the derailment.

The report also paints a clear picture of the myriad challenges: The software that allows inspectors to log track defects remains confusing to workers and allows for redundancies and inaccurate information. It’s a problem Metro is grappling with even after the agency fired a third of its track inspection department following the July 2016 derailment and amid reports that workers had been falsifying inspection logs.

Although the track inspection machine now spends more time on the rails, workers don’t use much of the data the machine is capable of collecting.

And there’s still not enough time to do track inspection work, in part because of extra logistical hassles caused by safety regulations that have been put in place in the past year.

In that period, Metro has become much more aggressive about reducing speed limits in areas of the system where tracks have defects, part of an effort to reduce the risk of derailment. But when inspectors stop to fill out the documents required to put a speed limit in place, it cuts into the time they have to finish the inspection.

New rules instituted to help protect workers from being struck by trains also result in longer wait times for permission to access the tracks.

[NTSB: Metro knew of potentially dangerous track conditions more than a year before July derailment]

The report demonstrates how, in the business of running a subway system, there are rarely easy solutions or quick fixes.

The internal report was not publicized by Metro but was posted to its website. The link to the document was removed minutes after The Washington Post asked Metro’s communications team about the report. The report was later posted on Metro’s “internal reviews” page.

At the board’s most recent meeting, Metro General Manager Paul J. Wiedefeld was asked about the state of the track inspection department. He acknowledged that issues remain, but he maintained that much has improved since last year, when a train derailed at the East Falls Church station, injuring at least one person and causing an estimated $150,000 in damage to the train.

The derailment occurred because a stretch of the tracks had fallen into disrepair, month after month, according to the National Transportation Safety Board. During subsequent investigations, it became clear that repairs were not performed in a timely manner and Metro’s inspection department didn’t even have an accurate picture of where problems existed on the tracks.

By the beginning of this year, Wiedefeld had fired 16 “track walkers” (rank-and-file inspectors) and five supervisors. Now, he says, the department is on the right path.

“We’ve brought in some outside help, we’ve established much different procedures that we follow to inspect and repair the tracks, we have more time to do the work with additional hours,” Wiedefeld said last week. “I’m very comfortable that we’ve moved quite a long way from a year ago, both on the conditions of the track and on the safety of the track.”

[Jan. 2017: One-third of Metro’s track inspection department has been fired for falsifying records, Wiedefeld confirms]

But the internal review offered a more nuanced picture of the progress.

The quality control team suggested that Metro cut down on the time used for pre-inspection safety briefings so workers could get more time on the tracks.

In one instance, the report said, a worker was contacted multiple times by the Operations Control Center to see when he would be clear of the tracks.

“The Control Center radioed . . . before and again during the interlocking inspection,” the report said. The report said the interruptions led “to an overly rushed inspection which prevented a full inspection of all the rails and fasteners.”

One quality control official noted that an inspector was ordered to halt his inspection so other employees could do maintenance work.

“There was almost another hour in which inspection could have been performed,” the report said. “This wastes resources and makes it more difficult for the inspection supervisor to meet Track Inspections obligations.”

That comports with similar issues raised by the Federal Transit Administration in a May inspection report, which noted that workers had to wait two hours to be given permission to step onto the tracks; by the time a dispatcher provided the go-ahead, they had only 10 minutes to investigate a problem before their window to be on the tracks expired.

The long wait times for track access exemplified a recurring theme in the internal report: Sometimes, “prioritizing safety” is a complex calculus of weighing competing needs.

The quality control unit also cited the track inspection department’s insufficient staffing and the impact it has had on the work.

“Inspectors do not have the sufficient manpower to inspect . . . fast enough” during regular service hours, the report said.

But Metro spokeswoman Sherri Ly said insufficient staffing is largely a problem of the past. There are 36 qualified inspectors at Metro — six more than the 30 required by the system, she said.

Metro’s quality control unit offered other suggestions for improvement in the report:

• The multimillion-dollar inspection machine should be outfitted with GPS to cut out the guesswork in describing the exact location of spots where defects are discovered.

• Workers should use more of the information that can be collected by that machine, which the quality control team said is underutilized.

• The software used to log defects allows for informational redundancies that confuse track maintenance workers. The software also forces inspectors to log defects individually, which can make it difficult to bump up a problem zone as an immediate priority if a slew of interrelated defects in one spot result in an urgent safety risk. Quality control officials recommended that the software be changed to allow for defects to be linked to one another, to “provide for better tracking.”

• Gauge rods, tools that are placed on the tracks to prevent rails from spreading apart, should be removed after 14 days. Right now, the report said, it sometimes takes longer.

The quality control unit had one more piece of advice for management: Track inspectors are now allowed to pick the set of tracks they are responsible for based on seniority. Inevitably, senior track walkers select the stretches of track that are shortest or easiest — and often, they pick the same stretch of track year after year.

Maybe, quality control officers said, it would be a good idea to force inspectors to rotate tracks each year, for one simple reason: “It is important to know that someone else will be inspecting the track after you,” the report said.

[Virtual inspections: A solution to Metro’s late-night service cuts?]