With “The Commuter,” director Jaume Collet-Serra and his frequent action muse Liam Neeson complete their unofficial “Planes, Trains and Automobiles” trilogy. In 2010, an uneasy taxi crashes into Berlin’s Spree and gives Neeson a bad case of amnesia in the ironically forgettable “Unknown.” In 2014, an alcoholic air marshal, played by Neeson, must stop a mysterious airborne killing spree on a plane in the surprisingly engaging “Non-Stop.” Now, with “The Commuter,” we find ourselves traveling with Neeson on a train, where a recently unemployed ex-cop-turned-insurance salesman gets caught in another murder conspiracy, one where a mysterious woman (Vera Farmiga) provides Neeson with a tantalizing offer that could either save or destroy his fragile family life before the train’s final destination.

One would assume there’s a formula in place now, and they wouldn’t necessarily be wrong. Neeson and Collet-Serra have indeed developed a bit of a working standard, which allows Neeson to continue his mature action-thriller career post-“Taken,” not dissimilar to Charles Bronson‘s robust gun-heavy late period career after the massive success of “Death Wish.” But to dismiss this latest Neeson/Collet-Serra collaboration as a disposable, unremarkable January non-starter that’s burning time and projector bulbs before finding a comfortable home inside Redbox machines would be to discredit just how knowingly, winkingly ridiculous this silly movie can be, and how Neeson and Collet-Serra are clearly having a grand time knocking around such nonsensical material for their mutual benefit.

Neeson plays Michael McCauley, the aforementioned down-on-his-luck former cop/insurance salesman, who is given the opportunity of a lifetime, even if it might cost the life of an unknown bystander on the train. When Michael is offered a $100,000 to identify a hidden passenger before the train reaches its final stop, he knows that it’s dirty money, but he also knows that it could help pay for his son’s college tuition, and that it could buffer some personal financial woes. But as he searches the moving train, surveying unfamiliar passengers, Michael gradually realizes the gravity of the situation, notably when commuters start dying on his watch.

Working with a seemingly perfunctory, by-the-numbers script by Byron Willinger, Philip de Blasi, and Ryan Engle, “The Commuter” is Neeson and Collet-Serra happily indulging in their every ludicrous desire. Preposterous as the film might be, its also a social commentary on the lower middle class and the fallout of the 2008 economic recession — particularly with Wall Street receiving a sneering, stern eye — and its very blunt and transparent in its intentions, refusing to let even the most casual viewer walk away without a clear, present understanding of what the filmmakers are communicating here.

Through its unambiguous message and its stylish flourishes, “The Commuter” finds a nice, strange balance between absurdity and sincerity. Its goofy enough to let sprinkled moments of well-filmed action insanity have the necessary punch, yet not too goofy as to override your suspension of disbelief. “The Commuter” is far from high art, but it at least knows what it is, and it plays up its shlocky tendencies enthusiastically, letting the third act earn its way to its completely ridiculous ending.

Neeson’s committed presence is a big benefit. At 65, his action days are waning, to put it mildly, but his Michael McCauley is weathered, concerned and buoyed by gravitas, even when the movie is aware of how downright outrageous the plot elements are becoming. Similar to Collet-Serra’s surprising “The Shallows,” the film is boosted by the director’s surefire confidence and strong attention to its cinematic flair. Indeed, much like “Murder on the Orient Express,” the stationary train location never loses its cinematic grandeur, as the director keeps finding enjoyable and inventive ways to keep the sterile location active and humming. And even when “The Commuter” literally goes off-the-rails, Collet-Serra drives the train with gleeful abandonment to logic or reason. You wish more filmmakers could willfully go this slapdash insane while still holding your marvelled attention. It’s to Collet-Serra’s underrated credit that he understands the value of dopey action thrillers and savors them, creating a moderately enjoyable ride with well-tuned quirks.

As far as Neeson’s recent action-thrillers go, “The Commuter” is decidedly somewhere down the middle. It intentionally lacks the nuances of “The Gray” and “A Walk Among the Tombstones,” but it avoids being as completely forgettable and derivative as “Run All Night,” another Collect-Sera/Neeson joint, and the “Taken” sequels. With a filmography as curiously inconsistent as Collet-Serra’s, “The Commuter” is a wild, mostly entertaining combination of the director’s general bag of tricks. It’s over-the-top and fun, even if in its own fleeting way, and by the time you’ve reached your stop, you don’t feel swindled. [B-]