East LA Interchange” refers to the world’s busiest highway system, as well as director Betsy Kalin’s first feature-length documentary after a series of niche efforts in queer cinema.

Her film offers a history lesson on the infamous barrio Boyle Heights and later the aforementioned highway system that reshaped it. Kalin’s subject matter bears the burden of being both too general and too specific. Casual viewers may not find themselves engaged with either the broad American history or the hyper focus on immigrant communities’ within a certain square mileage.

It must be said that – for nearly two decades – the neighborhood claimed the largest Jewish population on the West Coast. The barrio is Latino, yet one of the film’s most scenic lines comes from an elderly Jewish resident. Seated in front of a stark black background, she recalls: “We would get together and, under the streetlights, we would dance the hora.” Her distant gaze goes soft with remembrance.

Named best documentary at the Downtown Film Festival Los Angeles, “East LA Interchange” does succeed in the final third’s exploration of gentrification. The topic is an increasingly relevant one, as nearly 20 percent of low-income neighborhoods have experienced gentrification since 2000. Unfortunately, that aspect takes up only a small percentage of screen time.

Danny Trejo of “Heat” fame narrates the documentary, interspersed with interviews with residents and scholars. His deep gravel and the film’s editing inject energy where other areas are lacking. It is a story of American’s ever-shifting racial and economic landscape and the resulting costs. And it’s a lesson that needs to be taught, regardless of flare or excitement.