2024 ASEE Annual Conference & Exposition

Induced travel is the new travel that materializes in the aftermath of an improvement to transportation infrastructure (i.e., widening a road or adding transit). Accounting for induced travel is essential for accurately describing the long-term costs and benefits of a project. In particular, it suggests that congestion relief from new infrastructure will often be short lived. Do transportation engineering textbooks introduce students to this important concept? To find out, we conducted a careful review of seven textbooks and find that coverage of induced travel is often incomplete. Some textbooks omitted the idea entirely and those that did include it offered only partial coverage. Textbooks either defined the term, indicated its expected magnitude, used the concept in a problem set, or described the implications for practice. However, no single textbook included all these essential elements. Beyond this, all textbooks placed a greater emphasis on accommodating demand rather than managing it. Textbooks offered an asymmetric portrayal of how drivers adjust to traffic conditions. They tended to emphasize that drivers avoid congested areas and de-emphasized that drivers are also attracted to uncongested routes. Based on our review, we offer five criteria for developing high-quality teaching materials on this topic. Teaching materials should: 1) clearly define induced travel and distinguish it from other terms, 2) indicate the magnitude of induced travel we can expect, 3) feature the concept in problem sets to be consistent with engineering’s signature pedagogy, 4) describe the implications of induced travel for engineering practice, and 5) introduce students to foundational debates about transportation policymaking.