Commonwealth Avenue, also called Comm. Ave. in both the novel and real life, winds its way through Infinite Jest much as it does Metro Boston.
It begins as a parkway at the western edge of the Public Garden, heading out west through the Back Bay in a straight line, albeit with subtle vector changes at Massachusetts Ave. and again at Kenmore Square before surrendering to collinear Brighton Avenue just past Boston University at Packard’s Corner, where it plunges south and begins a leisurely eight-mile weave as a major thoroughfare, separating Brighton from Brookline and stretching to the far edge of West Newton.
This takes us past former Back Bay residences of the Incandenza family and individuals once close to them; past Nickerson Field at B.U. where Orin learns to punt and meets the P.G.O.A.T.; past the the giant Citgo sign which is “like a triangular star” for Gately “to steer by”; past the likely fictional Unexamined Life nightclub; past Ennet House and the Enfield Tennis Academy; past the definitely fictional Empire Waste Displacement catapults; through the East Newton hills where E.T.A. students run conditioning drills; perhaps even past the residences of Lateral Alice Moore and Kate Gompert, who live in Newton, or once did.
Comm. Ave is the street most frequently mentioned in the novel, but there is no signature scene with which it is associated. It is passively ubiquitous, like the water in Wallace’s beloved “This is Water” Kenyon commencement speech. (To my knowledge, Infinite Jest marks the first appearance of this charming bestiary in Wallace’s writing, as the unlikely wisdom of a recovering alcoholic biker who likes to be called Bob Death.)
Fittingly, there is no x-y coordinate which can be assigned to it: Commonwealth Avenue is not a true location, but an infinite sequence of them.