The preliminary Airports Council International rankings also place DIA as the third-busiest in North America for the fourth year, based on DIA’s record passenger traffic last year.

Capacity growth by the largest airlines and increased flight frequencies, combined with new carriers adding service, maintained DIA’s position. Aer Lingus launched flights to Dublin, Ireland, and Turkish Airlines launched flights to Istanbul, Turkey. DIA chief executive Phil Washington cited “continued, thoughtful growth” toward a target of handling 100 million passengers within the next couple of years by expanding global reach.

DIA’s record-breaking 82.3 million passengers traveling through the airport in 2024 represented a 5.8% increase compared with 2023. International passenger traffic at DIA is increasing faster – up 15% above the 2023 level to more than 4.6 million. That’s 46% more than the pre-pandemic international passenger traffic in 2019.

Worldwide, DIA’s passenger traffic placed behind the numbers in Atlanta (108 million), Dubai (92.3 million), Dallas/Fort Worth (87.8 million), Tokyo (85.9 million), and London (83.8 million).

The ACI airport rankings are based on data from 2,700 airports worldwide. DIA had the fourth most aircraft takeoffs and landings among the world’s airports last year, exceeded only by the aircraft movements at Atlanta, Chicago/O’Hare, and Dallas-Ft. Worth.

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The flight, UA2325, took off from Denver International Airport just after 7:20 p.m. Sunday. Less than an hour later, it was forced to return to DIA “to address a possible wildlife strike,” United spokesman Russell Carlton said.

The 153 passengers and six crew members were brought back to the gate loaded onto a new plane to resume their journey to Edmonton in Alberta, Carlton said.

None of the people onboard the Boeing 737-800 were injured.

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But when RTD’s trains slowed to 10 mph last summer, his commutes took as long as two hours.

Hunter, a Wi-Fi engineer, reverted to driving through traffic — fixating on rear bumpers from inside his burgundy Highlander or blue Subaru on Interstate 25, navigating shortcuts during jams, paying for gas, sacrificing the free transit pass his employer provided and missing the “peace of mind” he had on light rail.

“It’s disappointing,” Hunter, 60, said last week. “You lose your faith and hope of taking public transit. They have all this infrastructure in place. It is just not reliable.”

RTD officials plan to eliminate the slow zones, which they imposed for safety during a catch-up track maintenance blitz, before June 1. Light rail trains would resume normal speeds around 55 mph, ending an 11-month ordeal that has shaken public confidence in a taxpayer-financed rail transit system built to ensure mobility as traffic clogs metro Denver roadways.

And RTD leaders are counting on winning back Hunter and thousands of other lost riders.

Last year, what had begun as isolated instances of track corrosion and “rail burn” defects ballooned into a major engineering burden after RTD managers, under Colorado Public Utilities Commission scrutiny, adopted a stricter, industry-standard track inspection program. Starting in May, inspectors found more and more problems that, if left unchecked, could lead to crashes.

Light rail supervisors at first estimated that slow zones would end by September. Then they aimed for February. Trains have rolled at reduced speeds, in some areas, through this spring.

RTD maintenance crews have repaired 51 miles of tracks as of this month — about 42% of the agency’s 119-mile rail system, according to records obtained by The Denver Post through a Colorado Open Records Act request. They’ve replaced nearly two miles of track. That’s more maintenance work within a year than transit crews had done in the previous two decades.

Meanwhile, light rail ridership plummeted.

The 1.1 million monthly boardings reported for January 2024 decreased by 30% to 771,000 in January this year, agency records show. On the hard-hit E-Line that runs between central Denver and the southeast suburbs, ridership decreased by 50%.

Slow zones added to separate disruptions from downtown rail reconstruction work and other projects. RTD didn’t adjust published schedules to incorporate slow zone delays, bewildering riders, and bus shuttles between stations typically weren’t possible, managers said, due to driver shortages.

Smoothing tracks

RTD crews have made “great progress” in shoring up the system, agency officials announced last week.

The catch-up maintenance relied on a track-grinding machine that smooths away rail burn and corrosion. RTD inspectors have analyzed more than 6,000 track segments since May, records show, and agency officials say inspectors check all tracks twice a week.

However, the widespread rail burn — linked by RTD to wheels slipping on aging steel tracks — hasn’t been fully explained.

RTD general manager and chief executive Debra Johnson wasn’t made available for an interview. Dave Jensen, the assistant general manager for rail operations, was also unavailable. In an emailed statement, Johnson said proper maintenance will ensure good transit service in the future.

“Anytime there is a disruption to services, even temporary, the number of boardings can be impacted,” she said.

RTD officials didn’t rule out imposing slow zones again.

“Aging rail infrastructure necessitates ongoing maintenance, repairs, and upgrades. RTD’s rail network is continually aging and will require ongoing repairs in the future. All transit agencies undertake similar maintenance work, so this effort and speed restrictions are common,” RTD spokeswoman Marta Sipeki said in an email. “As RTD is able to fully resume light rail services without disruptions, the agency anticipates a return of customers.”

“My commute became more difficult”

In the last year, the slow zones brought havoc for transit-dependent workers around metro Denver. Some riders say they’re leery of trusting public transit, especially after RTD’s failure to update its schedules to incorporate slow zones.

If light rail trains resume normal speeds, life will improve, said Adriano Bamba, a Metropolitan State University of Denver student who works in a downtown FedEx store. The unexpected RTD delays made him late, he said, forcing discussions with supervisors about pay for lost time.

He’s optimistic, noticing fewer slow zones along the R-Line he rides from Aurora into Denver, he said. Yet illegal drug use on trains also deters riders.

“Someone will start smoking,” he said. “You could start yelling at them. Or you can change train cars.”

For Thomas Charles, 22, relying on RTD trains to get to work has meant waking up early to allow for a possible two-hour trip from his home in the south suburbs to an Amazon facility in Thornton. He leaves Lincoln Station at 7:30 a.m. and seldom gets home before 10:30 p.m. “You lose sleep and energy,” he said while waiting for a train last week.

Slow zones, combined with unannounced delays and train cancellations, made him late so often over the past four months that supervisors have warned him he could lose his job if he doesn’t line up reliable transportation. Taking an Uber costs $35.

“They’ve told me that multiple times. It does not feel good,” Charles said. “I am saving up for a car.”

University of Colorado Denver student Tim Reinicke, who lives in Parker, already had shifted to driving for part of his commutes. RTD buses between Parker and the Lincoln Station run only once an hour and aren’t synced with trains, Reinicke said.

Slow zones felt like “salt in the wounds,” he said. “My commute became more difficult.”

As he spoke, he was waiting for a train to get to his linguistics class at CU’s downtown campus. He learned that rail service had been suspended through noon after a car that went off a highway overpass crashed onto the tracks below, leading to a fatal collision with an RTD train.

“I don’t know how I’m going to get there,” Reinicke said, checking his smartphone.

“I want to try to avoid driving,” he said. “I don’t like driving. I don’t want to pay for parking. It costs $7.” Not to mention gas costs — “a big motivation” for riding light rail, he said.

But driving is more reliable. “When I have to drive, that is me — actively — not trusting RTD,” Reinicke said.

Willing to give light rail another try

The Greater Denver Transit advocacy group has questioned RTD’s track inspections and lambasted RTD’s schedules as “unworkable,” rendering light rail “virtually unusable for riders” after the sudden imposition of slow zones last June.

GDT co-founder Richard Bamber, a civil engineer who worked on the construction of RTD’s light rail system, said rail burn “is not age-related” and that solutions require analysis of the interplay of steel wheels on tracks and how operators drive trains.

“We’re almost a year into this, and if there might be more slow zones imposed, it tells me RTD still hasn’t completed enough inspections,” said GDT analyst Joe Meyer, an aerospace engineer. He concluded RTD light rail “is no longer a reliable option” for consistent commutes between his home in Five Points and his office in the Denver Tech Center.

Meyer shifted to buses or drove to his office to be on time for meetings. Last week, when he was frustrated to be “watching traffic, figuring out when to leave,” Meyer decided to try light rail again — only to find service suspended after the train-car collision.

He tried again Wednesday, boarding at Stout Street and taking a seat in the front car with three other riders.

South of the Colorado Station, the train slowed to a crawl. “We may be doing 15 mph,” Meyer said, looking out the window at I-25. “It’s frustrating to see every single car on the highway flying by. My time is valuable.”

But even with the slow zone, he arrived in about 50 minutes. “The upside of a working system is so advantageous that I’m willing to keep trying,” he said.

Similarly, in Lakewood — where commuting in traffic has become such a brain-addling experience for Hunter over the past six months — if RTD can end the slow zones by June 1, he says he will try light rail again.

“I cannot wait.”

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The car was pinned between the train and a wall, according to South Metro Fire Rescue. Officials confirmed one person inside the car died but didn’t say if anyone else was inside the car.

“At this point, it appears it was a single car crash with a driver, where the vehicle went off the road and landed near the RTD light rail tracks,” Lone Tree spokesperson Melissa Gallegos said in a statement.

The train operator and only passenger on board were not injured, South Metro officials said.

South Metro crews responded to the crash near RTD’s Lincoln Station at 10200 Station Way in Lone Tree at about 1:23 a.m. Tuesday, officials said. They said the car drove off an overpass near the C-470 and I-25 interchange.

RTD’s E Line was suspended and buses replaced part of the R Line during the crash cleanup and investigation, according to RTD.

Both light rail lines reopened at about 12:30 p.m. Tuesday after RTD completed an inspection of the track and retaining wall, RTD spokesperson Marta Sipeki said.

Lincoln Station, County Line Station, Dry Creek Station, Arapahoe at Village Center Station, Orchard Station and Belleview Station were all affected by the partial R Line closure.

Sipeki said passengers should still expect delays in the area through the afternoon as RTD works to get trains running along both tracks.

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But state regulatory documents show the derailment occurred after a steel wheel broke apart and that, after the train operator radioed supervisors, the crippled train kept rolling through RTD’s Yale Station before stopping near Hampden Avenue where tracks dip ahead of an overpass.

Train wheel failures can be deadly, as seen in 1998 near Hanover, Germany, where a crack in steel caused a high-speed train to derail and crash into an overpass, which collapsed, killing 101 people.

The RTD investigation of its Jan. 24, 2024, derailment and a subsequent Colorado Public Utilities Commission corrective action plan have not been made public. Neither have the investigations of other light rail derailments, including two in Aurora in 2019 and 2022 along the same curving stretch of track where multiple passengers were injured and a woman’s leg was severed.

RTD’s total 97 bus and train crashes in 2024 included a record seven train derailments, more than during the previous two years combined, according to RTD records obtained by The Denver Post under a Colorado Open Records Act legal petition. Over the past six years, an annual average of 113 RTD trains and buses crashed, a rate of one every 3.2 days.

The public should be better informed about the cause of derailments under a new law  — signed last month by Gov. Jared Polis — requiring the PUC to make RTD light rail accident investigations public if it would protect safety and health. PUC officials are tasked with implementing the law.

Meanwhile, Denver-based civil engineer Richard Bamber, who worked on the construction of the RTD’s rail transit system, is warning that the deterioration of RTD’s tracks — a problem that forced agency managers to impose safety “slow zones” where trains run at 10 miles per hour – could make wheels wear out faster. A founder of the public transit advocacy group Greater Denver Transit, Bamber said that if the RTD isn’t replacing worn-out steel wheels frequently enough, rider safety could be compromised.

“We have had at least one wheel fail, and things don’t normally fail in isolation. That’s why they need to check everything,” Bamber said.

“Did this wheel fail due to a manufacturing defect? Or did it fail because inspections and maintenance were not adequate? In both cases, the problem would affect multiple train wheels. Safety-first logic says you should treat the systemic problem and not the incident in isolation.”

RTD officials weren’t available to discuss train derailments and didn’t answer questions about whether changes were made after the wheel failure.

The RTD “will comply with the changes in state law and any regulations that are issued by the PUC,” agency spokeswoman Tina Jaquez said.

Derailments

None of the RTD’s seven train derailments in 2024 led to passenger or operator injuries. One of them happened when a vehicle hit a train, knocking its wheels off the tracks, Jaquez said in an email.

The Jan. 24, 2024, derailment just north of RTD’s Southmoor Station “resulted in a disabled train,” she said, repeating the language used in public service alert announcements while crews cleared tracks.

A required June 6 RTD staff report to the PUC summarizing accidents described the derailment: The light rail train “began shedding wheel/tire components and eventually experienced a catastrophic failure of one wheel/tire assembly and derailed,” the report said.

A separate PUC document refers to the undisclosed corrective action plan and says the train operator detected trouble and radioed a control supervisor, asking about possible train mechanical problems, yet “continued southbound from Colorado to Yale Station with significant performance issues.” Then, the train “experienced catastrophic failure of one wheel/tire assembly. Another tire was also affected.”

PUC recommendations included metal testing to determine whether the wheel was defective, giving train operators more leeway to stop without authorization from supervisors when they face potentially unsafe situations, reviewing RTD practices in getting rid of worn wheels, creating a standardized wheel procurement process, and increasing rail grinding (smoothing out bumps) on tracks.

In 2022, an RTD employee’s detection of corroded tracks downtown led to a PUC corrective action plan and eventual RTD toughening of inspections in line with industry standards — weekly inspections on foot or in a vehicle that moves slowly enough along tracks to allow accurate assessment of wear and tear. RTD began stepped-up inspections, leading to the imposition of the slow zones that have delayed transit for nine months.

Train wheels

If Colorado’s new law had been in place last year, metro Denver riders might have learned about the derailments and their causes, Bamber said. Around the country, other public transit agencies also need to know about problems to prevent disasters, he said, referring to the Federal Aviation Administration and National Transportation Safety Board systems for investigating aviation incidents and making preliminary and final reports public.

“If the RTD was finding problems, would you want to know? Would you want to read the accident investigation reports? That’s what this current secrecy prevents,” he said.

After the Aurora derailments, RTD officials determined that light rail operators were at fault.

State lawmakers crack down

Colorado’s new accident investigation reform law may not apply to past light rail crash incidents, depending on the regulations the PUC must adopt to implement the law.

State Sen. Faith Winter, one of the legislative leaders who pushed it through, said lawmakers have been talking with PUC officials and are confident that the agency will implement the law effectively.

If the RTD crashes and derailments expose problems, transparency will be crucial to prevent disasters and improve public transit, Winter, a Broomfield Democrat, said. “Seeing how those flaws are fixed adds to the greater trust of the public in our transit systems,” she said.

“It is essential to have this information and make the reports public so that we can establish what the corrective solutions are. Is it a tire problem? Is it the angle of that specific curve? Was it a driver issue? Without having access to the reports, we don’t know. And that leads to a lot of questioning about public safety.”

There were 824 delayed and 14 canceled flights at DIA as of 4 p.m., according to flight tracking website FlightAware.

Snow and ice is causing arriving flights to be delayed by an average of 90 minutes, according to the Federal Aviation Administration.

DIA officials posted a video of snow at the airport on social media and urged travelers to check with their airlines for delays or cancellations.

Southwest Airlines passengers were facing 282 delayed and 10 canceled flights, while United and SkyWest reported a combined 371 delayed flights.

This is a developing story and may be updated.

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The $22 million project will stretch from Alameda Avenue to 44th Avenue just south of the interchange with I-70 and include building higher walls, repairing expansion joints between the highway and bridges and installing new signs.

Most of the repaving will be done at night between mid-May and the end of October, officials said. Construction crews will replace 2,700 feet of concrete walls along I-25 adjacent to the South Platte River — work scheduled through January 2026.

Here’s what I-25 drivers will face:

U.S. 6 and Alameda ramp closures

Shortly after sundown Sunday, CDOT crews will start replacing walls along southbound I-25 between the U.S. 6 ramp and Alameda. They’ll work Sundays through Thursdays between 9 p.m. and 6 a.m., requiring overnight closures of the east and westbound U.S. 6 on-ramps to southbound I-25 and the southbound I-25 off-ramp to Alameda Avenue. Drivers will also face single-lane and highway-shoulder closures on southbound I-25.

Detours

CDOT crews are setting up detours. Drivers headed east or west on U.S. 6 will be routed onto southbound Kalamath Street to the Santa Fe/Kalamath on-ramp to southbound I-25. Drivers headed south on I-25 to Alameda will be routed onto the Santa Fe Drive exit and then across Mississippi Avenue and over the South Platte River onto North Santa Fe Drive and then Alameda.

I-25 lane closures

Once nighttime temperatures consistently exceed 44 degrees in mid-May — a threshold for laying asphalt — workers will begin resurfacing the highway. As many as three lanes in each direction will be closed at night, Sundays through Thursdays, until late October.

Drivers also may face delays and lane closures during the day and on weekends, depending on project needs, with closures timed to accommodate other events in the area.

CDOT supervisors said they’ll set up traffic cones and signs, including overhead electronic signs, to guide drivers.

The deal that Amalgamated Transit Union Local 1001 leaders negotiated with the RTD would provide a 6.5% wage increase this year, applied retroactively to Jan. 1. The drivers, operators, mechanics, and other transit workers would receive a 4.5% increase for each of the following two years.

ATU negotiators had pushed for wage increases by 7% each year for three years.

The 2,000 or so union members would have to approve the deal in voting this month, ATU president Lance Longenbohn said. If approved, it would raise the starting hourly pay for a new bus driver or train operator from $25.96  to $27.65 this year, increasing to $28.89 next year and $30.19 in 2027. The top pay would increase from $32.88 to $35.02 this year, then to $36.59 and $38.24, Longenbohn said.

RTD drivers “can find other jobs where they’re not getting cursed at and spit on, in some cases to make more and in most cases to make enough that it’s worth the difference,” he said. “It’s a hard job. You’re not just driving. You’re keeping an eye on people on the bus, answering questions, helping people with mobility devices.”

RTD has struggled to retain frontline employees. Shortages of available bus and train operators have limited the agency’s ability to help riders navigate disruptions as maintenance crews carry out catch-up work to repair deteriorating rails. Bus and train operators marched through Lower Downtown from Union Station to RTD headquarters at rush hour recently and packed an agency board of directors meeting demanding higher wages.

Photos showed passengers scrambling out on a wing above the smoke as ground crew members tried to get the bridge to DIA in place and positioned slides and ladders.

“Evacuation procedures will be part of the investigation,” an NTSB email said. The role of the bridge, in particular, “is something the investigators are looking into.”

An NTSB-led team has been investigating at DIA since the incident on March 13, when American Airlines Flight 1006 took off from Colorado Springs at 4:52 p.m., bound for Dallas-Fort Worth. It diverted at 5:14 p.m. to DIA after crew members reported engine vibrations. The aircraft landed safely and taxied to gate C38, where the fire broke out.

DIA ground crews went to the gate and doused the flames as 172 passengers escaped. A dozen passengers were taken to the University of Colorado Hospital in Aurora for treatment of smoke inhalation and minor injuries.

An NTSB study done 25 years ago of 46 evacuations over a two-year period found engine fires are the most common cause and that, even when flight attendants commanded passengers to “leave everything,” passengers often took their belongings. Nearly 50% of passengers interviewed for the study reported trying to remove a bag during the evacuation.

The FAA sets standards for airlines to follow in emergencies.

“Airlines determine how to do that, and flight attendants typically instruct passengers to leave all carry-on luggage in the cabin if they evacuate,” FAA spokeswoman Cassandra Nolan said. “FAA regulations require passengers to obey crewmembers’ safety instructions,” Nolan said.

American Airlines officials did not respond to requests to discuss what happened.

Airline crews undergo training to prioritize passenger safety and quick movement of people off the plane.

At Metropolitan State University of Denver, Aviation and Aerospace Science professor and FAA chief instructor Chad Kendall, a former commercial airline pilot for American Eagle and other airlines, saw the incident as a case study in the complexities of evacuating aircraft.

Beyond the question of which exits were used and crew members’ actions, “a crucial and unpredictable element is human behavior,” Kendall said. “Passengers often react instinctively under stress, which can either aid or hinder the process, he said.

“Even if the jet bridge was in use for passengers deplaning through the forward exits, the urgency and panic inside the cabin may have led passengers to independently initiate an evacuation through the over-wing exits,” he said. “Instinct takes over, and their primary focus becomes finding the nearest available exit to ensure their safety.” 

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The southbound BNSF Railway freight train jumped the track the afternoon of Oct. 15, 2023, after hitting a broken rail near a track switch just north of a bridge over I-25, the National Transportation Safety Board said in a final report. The area is about five miles north of Pueblo.

Twenty-one hopper cars loaded with coal derailed, hitting the bridge and causing it to collapse. Six railcars crashed onto the highway, killing 60-year-old California resident Lafollette Henderson, who was driving a semitruck under the bridge at the time. The crash caused $15.6 million in damage and also closed I-25 in both directions for four days.

The broken rail was likely caused by a mismatched weld that failed because a welder did not use the right materials, NTSB officials said.

BNSF welders are supposed to use a specific kit, known as a compromise kit, when welding rails that are slightly different heights – even as little as a fraction of an inch.

It doesn’t appear a kit was used when the rail was welded in May 2023, five months before the crash, leaving a gap at the base of the rail that filled with molten material, leading to cracks and the eventual break, according to the NTSB report.

“When interviewed by the NTSB, the welder who made the weld did not recall performing this weld several months earlier,” federal officials said in the report. “He was properly trained, demonstrated knowledge of when a compromise kit should be used according to BNSF procedures and reported that he had used them in the past.”

The rail broke after a test vehicle traveled over the track earlier that day, according to previous reporting.

After the accident, BNSF created a policy to analyze failed welds and retrain employees as needed. Welding supervisors also started conducting random monthly audits to confirm the correct materials are used, the NTSB said.

In a statement, BNSF officials said the company regularly conducts extensive inspections related to tracks, bridges, rails and weather events.

“…We are committed to continuous improvement and will carefully consider the NTSB’s final report and recommendations to more fully understand what lessons can be learned from this incident,” BNSF said in a statement.

No criminal charges have been filed in connection with the crash, according to court records. The Colorado Bureau of Investigation was not involved in the derailment investigation and the Colorado Attorney General’s Office does not comment on or confirm investigations, according to the agencies.

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