Tara Sager has been a daily MAX rider for seven years, for most of that time happily relying on the light-rail system as part of her commute between Hillsboro and Tigard.

So TriMet should be nervous when she says this: "Maybe I should start driving again."

Plagued with delays and disruptions, MAX is coming off its worst year in at least a decade for on-time service. One in five trips were late, according to numbers obtained by The Oregonian/OregonLive, and November was MAX's worst month since 2003 -- the earliest records were available -- for reliability.

Even though TriMet promotes MAX as a faster, more reliable travel option, buses were more likely to show up on time in eight of the last 12 months. That marked a reversal, of sorts. From 2008 to 2014, there were only six months when buses were more reliable than MAX.

TriMet says it's taking steps to improve. In an interview this week, Chief Operating Officer Doug Kelsey apologized for the year's performance and outlined steps he says will help get trains running on time.

They include shoring up the light-rail infrastructure, introducing policies and procedures that prioritize getting trains moving and increasing training for a relatively inexperienced corps of operators.

A fix can't come soon enough for riders like Sager.

She said delays have become routine and the frequent track and train breakdowns "maddening."

Her worst experience of the year came Dec. 23 after a cascade of disruptions: a faulty switch in East Portland cut off part of the Green Line; a collision between a MAX train and a car in downtown Portland caused delays for the Blue and Red lines; and a car stuck on the tracks near Union Station caused delays for the Yellow and Orange lines.

Delays by the numbers

TriMet says two-thirds of MAX delays are due to issues within the agency's control, like mechanical problems or operator error. Here's a breakdown of causes for delay between Dec. 1 and Jan. 5.

Vehicle mechanical failure: 148

Passenger issues (e.g. medical emergency): 48

Operating issues: 36

Switch issues: 14

Auto blocking tracks: 14

Biohazards: 7

Signal issues: 6

Collisions (TriMet involved): 6

Blocking collisions (non-TriMet involved): 6

Power outages: 5

Police activity: 5

Snow/ice: 3

Weather/trees fall in tracks: 2

Source: TriMet

Sager said she expected a train around 7:20 p.m., but didn't see one roll through for another 90 minutes. She estimates she got home around 10 p.m.

"I love TriMet," Sager said "But it's been frustrating enough that I've been thinking, gosh, maybe I should start driving again. If this doesn't turn around, I'm going to have to consider it."

That's problematic sentiment for TriMet. Light rail is appealing to transportation planners in part because it attracts new riders who wouldn't otherwise take transit.

But that means they're often more fickle.

"Typically, light rail has more of these riders with a choice," said Aaron Golub, an associate professor at Portland State University who studies public-transportation planning. "When service is not what they want, they can switch. They're probably more sensitive to these kinds of performance issues than other riders."

Service disruptions could hit a critical mass where commuters begin to defect, Golub said, though the MAX isn't shedding riders yet. In fact, thanks in large part to the opening of the Orange Line in September, ridership is on the rise.

Kelsey, brought on as TriMet's chief operating officer in late November with a mandate to improve reliability, said the agency has already set aside $11 million for projects to shore up its infrastructure.

"Yes, we have a problem," he said. "And I think the organization identified it a while back and is working on it."

Kelsey said it's also working with an unusually high number of inexperienced MAX operators after recent retirements, and about 30 percent of the operators have less than a year under their belts. Kelsey said TriMet needs to increase training for those operators.

TriMet needs to be able to get moving faster after a service disruption, Kelsey said, by reexamining its own procedures and working with other organizations like local police, fire and road maintenance agencies.

For example, Kelsey said he met with officials from the city of Portland and transit police officers this week to discuss an incident where a tree fell, blocking trains in downtown Portland for four hours before the tree could be removed. (Kelsey said he was on a bus that got stuck in the resulting gridlock.)

"Four hours when people need to get home is not good enough," he said. "We need to get to that NASCAR approach. Time's tickin'."

Kelsey said he'd like to see trains running on time 90 percent of the time, rather than the 75 percent seen in December. The last time reliability hit the 90 percent mark was February 2007, and the average since 2003 is 86 percent.

But even though added complexity from system expansion played a role, he said the agency shouldn't hold off on even more expansion before meeting that goal.

"I think the degree that we need to improve the system and shore it up should not be tied to expanding service to those who don't have it already." He said. "I think it would be wrong to connect a short-term dot to longer-term, region-shaping conversation."

For customers like Sager, Kelsey offered an apology and a plea to stick with the agency as it tries to improve.

"As the new COO here for 30 days, I apologize," he said. "I'm a user of the system, and it's happened to me. We want to get better. Help us get better, and keep using TriMet, because we want to be your first choice."

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus