The sequence of events is as predictable as it is frustrating.

Snow begins to fall along Interstate 84 in the Blue Mountains between La Grande and Pendleton.

The freeway gets slick.

Vehicles — most often commercial trucks, and often trucks that don’t have traction chains installed — lose control or momentum.

The lanes in one direction, and sometimes both, are blocked.

And once again the main travel route through Northeastern Oregon is closed.

When the freeway is blocked for more than a few hours — and this is often the case when trucks are involved, as they’re more cumbersome to move than passenger cars are — the closure can extend for more than 150 miles. As safe parking areas for commercial trucks are claimed in, say, La Grande, the Oregon Department of Transportation frequently has to close the freeway at Baker City and, as the domino effect continues, in Ontario.

The effect works in the opposite direction, too. A couple crashes in the eastbound lanes in the Burnt River Canyon between Durkee and Huntington can trigger a cascade of closures starting in Baker City and later spreading to La Grande and Pendleton.

Weather-related closures on I-84 aren’t a new phenomenon, to be sure.

Blizzards, particularly through passes such as Ladd Canyon and the Blue Mountains near Meacham, can create whiteouts so severe that closing the freeway is necessary.

But although ODOT doesn’t have detailed historical data about the frequency of I-84 closures in our region, even a cursory review of media reports shows that the freeway has closed more often in the past several years than in past decades — and in conditions that aren’t particularly treacherous.

As mentioned above, it hardly rates as a surprise when the freeway closes, even during a relatively modest storm such as the one that descended on the Blue Mountains Monday evening, Dec. 13.

A cold front brought a few hours of heavy snow, but this was no extended blizzard that cut visibility to the length of a truck trailer and made it dangerous for all vehicles.

ODOT’s press release announcing the closure noted that the culprit was “multiple spun out trucks” in a 3-mile section of the westbound lanes between La Grande and Meacham.

The closure, fortunately, was relatively brief, lasting about four hours.

Yet it was also the latest example of how fragile this vital transportation pike seems to have become. It’s not an exaggeration to wonder whether it’s possible to get through even a modest storm — of which we can expect several in a typical winter — without a closure.

The culprit in Monday’s closure — unchained trucks — is a common one in freeway closures, said Tom Strandberg, a spokesperson for ODOT in La Grande. In hopes of encouraging drivers to put on chains, in late September the state doubled the fine for failing to comply with the chain requirement, from $440 to $880. That’s a reasonable change. Unchained trucks not only are responsible for many freeway closures, which is at best annoying, but worse, they also pose a threat to other drivers.

The problem isn’t limited to commercial trucks, certainly. All drivers on the freeway during winter need to be prepared for snow and ice, either by installing traction tires or by bringing chains. And all motorists should drive with caution, according to the conditions.

Over the past couple decades, ODOT has done many things to try to make I-84 safer, including building a third lane on steep grades such as Ladd Canyon and Spring Creek, installing electronic signs to warn drivers of bad weather, and improving chain-up zones.

Those are worthwhile improvements. But none can replace plain old common sense.