Despite the challenging journey, Muriel and Alexander assist Macon in reconnecting with the world. As his bond with Alexander deepens, Macon experiences "a pleasant kind of sorrow sweeping through him. Oh, his life had regained all its old perils. He was forced to worry once again about nuclear war and the future of the planet."

In this novel, Tyler amusingly examines her characters' constrained lives when they choose not to venture beyond the familiar boundaries of their homes, families, or countries. The protagonist, Macon Leary, learns throughout the narrative that genuine living involves welcoming new and varied experiences.

Another recurring theme in Tyler's work is the balance of order in life—how much is necessary for maintaining control and how much stifles spontaneity. Macon, for instance, believes his knack for organizing his life helps him deal with the hassles of travel, his wife leaving, and the tragedy of his son's death. Yet, this order actually prevents him from expressing his emotions. In this and other Tyler novels, characters like Muriel Pritchett, who either resist excessive order or thrive in seemingly chaotic settings, are admired for their emotional freedom. In this story, Macon's life, dictated by his "systems," is disordered; he struggles to function or think clearly. It is only when he moves into Muriel's cluttered but cozy apartment that he shifts from isolation to openness.

Being open and caring carries inherent risks. To love means to risk experiencing loss, yet, as Tyler demonstrates, isolation only provides a false sense of security. It does not protect against life's unpredictability or its pleasures and still exposes one to its difficulties. Macon is heartbroken when his son is killed during a robbery at Burger Bonanza; he deals with his grief by rigidly controlling his emotions, behaving logically by mowing the lawn and giving away his son's possessions. Initially, he avoids forming a relationship with Muriel's son to steer clear of the potential pain of loss once more. However, until he allows himself to build a connection, he misses out on the love and sense of being needed that the boy could offer.

The centrality of sibling relationships, a common theme in many of Tyler’s novels, is the backdrop against which the events of The Accidental Tourist occur. It is also the litmus against which Tyler measures the degree of change occurring in her characters. In The Accidental Tourist, Tyler explores the effects people have on one another and the changes wrought by their interactions.

Julian, the quintessential preppy playboy, is enthralled by the homey atmosphere in the Leary house. He abandons his single life for a pedantic upper-middle-class world. Driven by his desire, Julian even manages to learn Vaccination, the only spouse to do so. For her part, Rose steps out of the groove in which she appears firmly entrenched and goes sailing on the Chesapeake.

When Sarah first leaves Macon, his grief over Ethan’s death and his own sudden bachelorhood nearly overwhelm him. When he moves into the working-class neighborhood in which Muriel rents a broken-down row house, he leaves behind a persona that is at least partially an artificial construct formed during his courtship of Sarah. Muriel’s flamboyance, her inner strength, and her joie de vivre in the face of nearly overwhelming hardship allow Macon at once to heal and to become, as Muriel calls him, soft-hearted. The original accidental tourist, Macon even finds himself extolling the virtues of San Francisco to a weary native Baltimorean who is a devotee of Macon’s books.

The Accidental Tourist is, of course, a metaphor for Macon’s life. He is passively swept along by events. While he is a competent and basically good-hearted man, Macon lacks Muriel’s inner strength. Through her influence, he is forced finally to make decisions in his life.

With its diverse historical traditions and distinctive neighborhoods, Baltimore provides a rich background for Tyler’s eccentric characters. Two sections of this multifaceted city are given clarity in The Accidental Tourist, Macon’s upper-class Logan Park and Muriel’s inner-city neighborhood of row houses. Before he meets Muriel, Macon’s entire life is spent in an old neighborhood of detached houses and tree-lined streets. The houses are spacious and private compared to Muriel’s domain, which consists of decrepit row houses with fake stone fronts, families sitting on front steps leading directly to the pavement, and unemployed men standing on streetcorners making small talk. Macon is a visitor in a strange world, a world in which he initially wonders how anyone can feel safe, but a world that ultimately he finds vibrant and thriving.

Social class consciousness permeates The Accidental Tourist as it does Baltimore. Because of their different classes, Macon’s family disapproves of his relationship with Muriel. His brothers refer to her as “this Muriel person,” and Sarah tells Macon that with Muriel he will be permanently on the fringe, a member of one of those couples who fit nowhere. It is a measure of Macon’s growth that he rejects these class biases and makes an active decision to return to Muriel.