Off Broadway at the Shed, Ralph Fiennes is glorious in David Hare’s sputtering portrait of the man who paved New York.I doubt I’d have enjoyed meeting the real Robert Moses, New York’s paver of highways, evictor of minorities, eminent domain eminence and all-purpose boogeyman. But it’s a huge pleasure to meet him, in the form of Ralph Fiennes, in David Hare’s “Straight Line Crazy,” which opened on Wednesday at the Shed.Whether the creature Hare and Fiennes create has anything to do with the creature that created modern Gotham remains, for a while, an irrelevant question. Moses’ actual demeanor and utterance, as portrayed in the nearly 1,300 pages of Robert Caro’s biography “The Power Broker,” are little in evidence at the Hudson Yards theater.Fiennes is too gloriously entertaining for that. Melodramatic in the old-fashioned sense, a hero or villain from an operetta or Ayn Rand, he crows his lines like a rooster, albeit in an accent suspended somewhere between East Anglia and Texas. With his nose pointing straight up and his chest pointing straight out, he’s a figurehead on the prow of a ship that can slice through icebergs as easily as red tape.Also through consonants: When he says “boardwalk” — a thing he despises, with its “so-called amusements” and “lox and bagel merchants” — the word has three syllables: the board, the wal and the k.So what if Moses is racist, antisemitic (though Jewish by birth) and an unabashed elitist who aims to advance ordinary people’s fortunes “without having any respect for their opinions”? Here he is wit and pith personified — and why would he not be, with lines honed by Hare in high-gloss mode?Usually that high gloss means Hare is up to some undermining; in plays like “Plenty,” “The Judas Kiss” and “Skylight,” good badinage almost always means bad faith.But in “Straight Line Crazy,” the connection is unclear, forcing you to ask why such a progressive playwright would spend even half a play valorizing a man who, among many other practical atrocities, displaced 7,000 families to clear space for Lincoln Center and 40,000 residents to build the Cross-Bronx Expressway. A clue in the script: “Moses’ life is so prodigious and his reach so great,” Hare notes, “that I have chosen to concentrate on just two decisive moments in his extraordinary career.”From left: Danny Webb as Gov. Alfred E. Smith, Fiennes and Judith Roddy as Finnuala Connell in the play, directed by Nicholas Hytner and Jamie Armitage.Sara Krulwich/The New York TimesApparently, one act will try to counteract the other, so it makes sense that the production, directed by Nicholas Hytner and Jamie Armitage for the London Theater Company, should introduce us to Moses in 1926. At that time he is merely the chairman of the Long Island State Park Commission, and his antagonists are not yet sympathetic proles but out-of-touch gentry.These are the owners of Nassau County estates whose gorgeous seclusion, not to mention their orchards, are threatened by plans for the Northern and Southern State Parkways. The play’s first substantial scene is in fact with a (fictional) Vanderbilt, supplied with a big-eared butler named Fergus and an even bigger sneer.“Leave him at the end of the drive,” this Vanderbilt (Guy Paul) instructs the servant after dispensing with Moses.But of course it’s Moses who dispenses with Vanderbilt. In their scene together and in the long one that follows, at a headquarters that serves as a hive of urban planning, the power broker is shown breaking under- and overlings like twigs to get his way.I say he is “shown”; he is not dramatized except to the extent he is self-dramatized, with prompts from those underlings. (Their interruptions of “Why?” “What do they do?” and “What’s that?” amount to dramaturgy by laxative.) Perhaps because they too are fictional, and purpose-built, they have few characteristics except those that pertain to Moses: Ariel Porter (Adam Silver) is the meek one who backs off every argument, and Finnuala Connell (Judith Roddy) is the spunky one who stands up to him, at least on small points.It’s not until an official overling arrives that any actual drama occurs. He is Gov. Alfred E. Smith of New York, a populist Democrat who is Moses’ patron and also, one begins to suspect, his patsy. That piquant combination, along with Danny Webb’s hilariously earthy take on the governor, gives the interaction between the men, needling each other among the maps and models of Bob Crowley’s set, the unlikely spin of a Mutt and Jeff comedy starring Laurence Olivier and Jimmy Durante.Helen Schlesinger as Jane Jacobs, the journalist and urban theorist, fails to emerge, as she did in life, as Moses’ greatest foil.Sara Krulwich/The New York TimesWhat’s going on beneath the comedy is less funny: On the theory that no one will tear up a road once it’s built, even if they’d have forbidden it beforehand, Moses orders construction to proceed on the parkways without having obtained the governor’s approval. That this is offered as an amusing example of flair and determination instead of a warning about subterfuge and megalomania means that Hare has either fallen under the Great Man’s spell or wants to make sure the audience has.Surely, you think during intermission, as you study the weird intrusion of the mall-like Hudson Yards into the city’s urban fabric, things will turn around in the second act, which the program tells you is set in 1956. That’s when Moses’ plan to extend Fifth Avenue through Washington Square Park met with fierce resistance from a new kind of opponent: the “minstrels and artistic women with handbags” of Greenwich Village. Cue Jane Jacobs.Alas, that journalist and urban theorist, who has so far popped up merely to say hello, fails to emerge, as she did in life, as Moses’ greatest foil. It’s a strange choice to make Jacobs (Helen Schlesinger) a minor character. Perhaps because of the inconvenience of history — the two never met — we are denied a direct confrontation, and with it a satisfactory climax.Instead, Hare goes uncharacteristically soggy, hauling Moses’ alcoholic wife into the conversation for pathos and having Finnuala, after decades in service to the builder’s vision, finally repudiate it. Moses loses on minor, mostly made-up points, not the knockout that Jacobs, Caro and time actually delivered.But even as the directors’ invention fades along with Hare’s — the community meetings, full of serious nodding, are especially silly — Fiennes never falters. His Moses, like his performance, becomes a car in search of a road, gunning the engine with nowhere to go.That’s no tragedy. The play is still a pleasure, and Moses is still in the doghouse. The man who, in Hare’s formulation, thinks cars are the “can opener” to the tin that is America would not recognize a Manhattan that after decades of discussion is soon to institute congestion pricing.If the efficiency of the brute is often superior to the fecklessness of democracy in getting things done, it is not always as lasting — which is reason enough to see “Straight Line Crazy.” In the midst of what feels right now like the losing fight of progressivism, it’s worth peeking at the devil, with fear and envy and a little schadenfreude.Straight Line CrazyThrough Dec. 18 at the Shed, Manhattan; theshed.org. Running time: 2 hours 30 minutes. More