[5] The film, which begins, ends, and occasionally combines with live-action, explores the often surreal fantasies of a young New York City cartoonist named Michael Corleone, using pinball imagery as a metaphor for inner-city life.

The unemployed Michael dabbles in cartoons and often wanders throughout the city to avoid family skirmishes and to artistically feed off the grubbiness of his environment.

Shorty throws Bongo out and then brutally kills him soon after, while the bar's white manager abusively confronts Carole over this; provoking her into quitting.

Meanwhile, Angie manages a strike at a mob-controlled factory, but when he reveals his plan to replace the strikers with unemployed black workers, the Godfather abandons him in disapproval.

In 1969, Ralph's Spot was founded as a division of Bakshi Productions to produce commercials for Coca-Cola and Max, the 2000-Year-Old Mouse, a series of educational shorts paid for by Encyclopædia Britannica.

"[8] Bakshi found Krantz's claims to be dubious, as the producer had recently purchased a new BMW and a mansion in Beverly Hills.

Because Bakshi did not have a lawyer, he sought advice from directors he had become friends with, including Martin Scorsese, Francis Ford Coppola, and Steven Spielberg, asking them how much they made on their films.

[8] Bakshi began pitching his next project, Harlem Nights, a film loosely based on the Uncle Remus story books, which eventually became Coonskin.

[8] During the film's production, Krantz attempted to maintain some level of control by issuing memos to Bakshi and other artists requesting various changes.

[8] Ed Bogas and Ray Shanklin returned to write and perform the film's score, as they had done for Bakshi's previous feature, Fritz the Cat.

[11] Inspiration for the film came from penny arcades, where Bakshi would often spend his time playing pinball, sometimes bringing his 12-year-old son Mark.

[8] Heavy Traffic began a tradition in which Bakshi would write poems before beginning production on each of his films, starting with Street Arabs.

"[2] Because Bakshi wanted the voices to sound organic, he experimented with improvisation, allowing his actors to ad lib during the recording sessions.

[8] According to James Bates, the voice of Snowflake, "I said, 'How about a little Wolfman Jack, Charles Nelson Reilly, Pearl Bailey and a little Truman Capote?'

Kausler says that a sequence was animated in which the viewer sees "the key in the ignition metamorphose into a penis entering Maybelline's vagina".

[12] Kausler also states: I covered this scene with another one of the key changing into the fat black guy, and the ignition slot turning into Maybellene.

The film also featured songs by Sérgio Mendes and Brasil '66, The Isley Brothers, Dave Brubeck, and Chuck Berry.

[12] Roger Greenspun, of The New York Times, wrote in his 1973 review: 'People who felt that his earlier feature, Fritz the Cat, merely debased a cherished original, can now judge Bakshi's development of his own material.

'[1] Charles Champlin wrote in the Los Angeles Times that the film was 'a further leaping step forward for American animation; at that, Heavy Traffic is, in its furious energy, uncomfortable to watch as often as it is hilarious'.

[14] Gene Siskel of the Chicago Tribune gave the film three stars out of four, and wrote that 'by mixing live-action and animation, Bakshi generates a willingness in us to be moved in some 'aw, shucks' ways that are corny, but feel good'.

[15] The Hollywood Reporter called it "shocking, outrageous, offensive, sometimes incoherent, occasionally unintelligent; however, it is also an authentic work of movie art and Bakshi is certainly the most creative American animator since Disney".

[8] Gary Arnold, of The Washington Post, was negative, calling the film 'ostentatiously ugly' with 'nothing pleasurable or liberating in [Bakshi's] style of mockery'.