In "Coast to Coast," a rowdy and progressively shoddy romantic chase comedy, Robert Blake plays an independent trucker on the run from his vindictive estranged wife.

He picks up more trouble in the chattery, wild-maned form of Dyan Cannon, a Beverly Hills housewife who has just escaped from an exclusive Eastern asylum where she was committed by her unscrupulous estranged husband, psychiatrist Quinn Redeker. The encounter takes place when the runaway wife, Madie, flags down the runaway husband, Charlie, on a rainy night in Pennsylvania.

Charlie is soon pursued by a brute (Bill Lucking) trying to repossess his rig. Madie is soon pursued by private detectives (Maxine Stuart and Dick Durock) hired by her husband. On the way to a showdown with Madie's husband, the runaways contrive to elude their pursuers, overcome their misunderstandings and fall in love.

"Coast to Coast," has engaging possibilities and performers, but it does far too much sputtering and stalling to offer consistent or satisfying lighthearted diversion. Stanley Weiser's script will not be remembered as a model of wit and sophistication. The time that might be devoted to amusing character development seems to get frittered away on protracted slapstick shenanigans or picturesque traveling shots accompanied by Country & Western ballads.

Charlie and Madie are worlds apart socially as well as temperamentally, but class origins and attitudes don't seem to supply the movie with any humorous inspiration. The climactic episodes are so poorly conceived and arranged that they play havoc with the willing suspension of disbelief. Madie and Charlie are supposed to be driven apart over an issue that really ought to draw them closer together -- Charlie has conned the detectives out of the reward money offered by Madie's husband. After she takes off with inexplicably wounded feelings, the movie must play tedious catch-up, which consists of Charlie seeming to hitch a nonstop ride with an elderly motorcyclist across several Western states before pulling even with Madie and then clinging to the side of his truck for what appears to be hundreds of miles before the concluding demolition spectacle. Ironically, this behavior invites more than a fleeting suspicion that maybe her husband wasn't totally lying about her mental condition when he had her put away.

The skimpiness of the material is accentuated by Joseph Sargent's skittish style of direction, which seems to be darting around looking for an appropriate vantage point and playing rhythm without quite finding them in any single sequence. Even in the confined setting of the truck an intimate comic tone seems to elude or perhaps bore him.

Despite their likable, eccentric personalities and considerable skill, Blake and Cannon don't mesh as romantic comedy partners. A major stumbling block is that their characters are conceived at an incorrigibly childish emotional level. You never quite think of Madie and Charlie as grown-ups, and when you see them running away from the demolished Beverly Hills estate in the closing moments, the impression seems decisive. It's as if The Little Rascals were hightailing it after accidentally breaking a window.

(Incidentally, Dyan Cannon's fabulous, cascading mass of curls has become a scenic wonder as awesome as Niagara, but it also poses certain problems. Although she is allowed to prevail in her wrestling match with Maxine Stuart, that head of hair would seem to put her at a certain competitive disadvantage. In additional, the sheer, spreading abundance of it threatens to block our view of her face.)

The supporting cast seems rather more forceful and amusing -- especially Redeker as the conniving husband and Michael Lerner as his Eastern colleague-accomplice, a psychiatrist kidnapped by Cannon in order to make her escape at the outset. These comic medical scoundrels reinforce a curious trend: Psychiatry is the most discredited profession on the screen at the moment. Prior to the Redeker-Lerner conspiracy, we had Klaus Kinski fornicating with his patients in "Schizoid" and Michael Caine deviating drastically in "Dressed to Kill." Combined with Frederick Crews' recent debunking article in Commentary "Analysis Terminable," the impression grows that Something Is Up which portends hard times for shrinks.