On a cheap Target bike, almost on a whim, a young woman from Boston sets out to cycle across America “for cancer.” Declaring herself incapable of loving another human, Penny desserts her neurotic boyfriend, hooks up with a bunch of strangers and pedals off on a quest for salvation.

Paradoxically, the hero of Mike Lew’s “Bike America” is already 4,000 miles from home when her journey begins. Lost, unmoored and on a path of self-destruction, Penny burns every bridge she crosses and though it may be almost chemically impossible to remap the wiring of her brain, the comedic bedlam she creates turns this Alliance Theatre world premiere a one-of-a-kind theatrical adventure.

We should probably say right up front that “Bike America,” the winner of the Alliance/Kendeda National Graduate Playwriting Competition, uses the “f word” a lot, contains brief flashes of nudity and requires its five biker characters to traverse the stage on little one-wheeled bikes, a theatrical device that is probably a lot harder than it looks.

Writing in an original voice, preoccupied with time-honored themes of modern literature, Lew, a Juilliard School graduate, is very good at sketching raw and irreverent comedic shenanigans. But he is much less successful at patching them together into a cohesive whole. Not one to cop to conventions of sunny affirmation, Lew ends his adrenalin rush of a play on a tragic note. Since Penny reveals her destiny at the beginning, this will not come as a surprise to good listeners. But it may feel more like a dead-end splat than it ought to.

From Boston, over to Ohio, down through Kentucky and Tennessee, and across the mighty Mississippi River, Penny (Jessica DiGiovanni) and her companions wreak havoc wherever they go. Led by biker geek Ryan (Tom White), the group includes Tim Billy (Brandon Hirsch); a lesbian couple named Rorie (Je Nie Fleming) and Annabel (Marilyn Torres); Penny’s tag-along boyfriend, Todd (Matt Nitchie) and the Man with the Van (Maurice Ralston). Fleming, Torres and Ralston are charged with playing the various eccentrics the group encounters along the way and they prove themselves to be a delightfully versatile bunch.

Directed by Moritz von Stuelpnagel, “Bike America” explores, with considerable comedic virtuosity, notions of identity, conformity, alienation, group dynamics, hierarchy, politics, promiscuity, mental illness, nihilism and despair. It even makes a statement on same-sex marriage. (Rorie and Annabel want to make it official in every state.) Lew doesn’t, however, give us much of Penny’s backstory or explain her mania and brokenness.

Framed by set designer Andrew Boyce’s elegantly graduated proscenium, the action occurs on a bare stage, except for snapshots and signposts that fly in and out of the frame to tell us where we are from time to time. Costume designer Melissa Schlachtmeyer dresses the company in appropriate biker gear, T-shirts and, for the Man with the Van, slacker scruff. Kendall Simpson designs bits of original music and loops it into a hiply alternative soundscape that includes snippets by the pop band Clap Your Hands Say Yeah, among others.

The play runs at a crisp 90 minutes and though the bikers take an exhilarating survey of the American landscape, it is a sad inevitability that poor Penny makes little progress at all. As a portrait of a young woman’s jittery fall through space, “Bike America” is a dark comedy that ultimately offers little solace.

Theater review

“Bike America”

Grade: B-

7:30 p.m. Tuesdays-Thursdays. 8 p.m. Fridays-Saturdays. 2:30 p.m. Saturdays-Sundays. 7:30 p.m. Sundays. Through Feb. 24. $20-$35. Alliance Theatre, Hertz Stage, 1280 Peachtree St. N.E., Atlanta. 404-733-5000; alliancetheatre.org

Bottom line: A bumpy dark comedy.