Beefy opening-credit backbeats of “99 Problems” aren’t all that’s chopped and screwed in Tony Scott’s remake of The Taking of Pelham 123. Downshifting from Jay-Z to lazy, Scott grinds generous, genuine tension and character development to a virtual halt.

Scott foregoes the peyote-tablet visuals of Domino and Man on Fire for his usual kinetic, but not nausea-inducing, ways. There are food-poisoning hallucinations that made more sense than those films.

Co-stars Denzel Washington and John Travolta trade dialogue blows, leanly shucking and weaving around ideas of do-gooders, destiny and the daily grind. Plus, there’s verisimilitude in seeing subway-train hostages through Plexiglass windows caked with a city’s collective grime.

But Scott and screenwriter Brian Helgeland follow a perfectly paced and performed first hour with an express line straight to meathead territory. Pelham’s many strong points are junked in favor of cheap ticking-clock thrills.

Speaking of that clock, Scott splatters it onscreen with other graphics. There are moments in Pelham that look like Google Maps splitting a crack rock with Charles Schwab’s “Talk to Chuck” text boxes.

As Don Henley once said, everything can change in a New York minute — especially for a subway motorman hijacked by an angry dude with a Fu Manchu. Ryder (John Travolta) has dagger-edged sideburns, ropy tattoos, blazing firepower and an inch-short temper. With thugs’ help, he holds hostage a passel of commuting passengers on the Pelham 123 line.

Once Ryder takes a tactical advantage, he yaps back to the frantic dispatcher on the other end of the line. Garber (Washington) is a cola- and coffee-swilling mass-transit lifer currently under investigation for taking a bribe. Temporarily demoted to dispatch, Garber becomes an ersatz investigator and armchair psychiatrist.

Garber must hold court, and save lives, until the police and the mayor arrive. Wisely, John Turturro’s Camonetti isn’t a piggish cop, but a collaborative strategist, and James Gandolfini offers comic bureaucratic counterpoint as a beset mayor.

Not since True Romance’s pairing of Christopher Walken and Dennis Hopper has there been such joy in hearing two actors merely talk in a hectic Tony Scott movie. As two men perched toward uncertain leaps, Washington and Travolta teeter and totter. Their byplay both forges a curiously symbiotic bond and forwards the plot; Ryder wants $10 million in one hour before he’ll start picking off hostages.

Travolta does his patented smiling, laughing psycho act, but Ryder truly feels like a dangerous, sparking live wire. His tantrums double as taunts, and Travolta curses so convincingly, it’s like he’s channeling the verbal volume of Samuel L. Jackson. Meanwhile, Washington avoids his singsong patter and sturdy swagger for a sound that’s sadder, wearier, grayer in the soul and palpably middle class.

When Ryder goads Garber into gabbing about his possible guilt, Pelham hits its apex — linking the men’s desperation, attitudes and failings in a beguiling fashion. Fatally, this scene comes far too early in the movie.

Pelham dips when its casually multicultural Noo Yawk aspects (akin to Spike Lee’s far-superior Inside Man) turn into ethnic and social grandstanding on the train. Look! That black man’s no gangster! That mother’s no mouse! And it overinflates advice Camonetti gives Garber: “Just deflect, if you can” could easily be the mantra of Joe Sixpack to ward off a number workaday job.

But it barrels downhill once Helgeland and Scott re-envision the original film’s botched money-run sequence. Here, it’s thrown off by stunt-team accidents so heinous they make the NYPD out to be the eastern seaboard’s worst drivers. Two separate characters wonder why a helicopter wasn’t used in the first place.

There’s also no misdirection, no red herring, no real interest in anything beyond the first hour’s setup and secrets. More infuriating than how Helgeland telegraphs a big twist in Ryder’s plot is that there’s no appropriately timely anger or rage behind it.

Worst of all, Pelham betrays the calculated characterization by Washington and Travolta – turning them from chess masters into Rock ’Em Sock ’Em Robots for an interminable final-act foot chase.

With the barrage of flipping cars and gruesome gunplay, it’s like watching a brash, loud Viagra ad spliced into the modulated cool of a Michael Mann film. This is the great disappointment of the summer so far.