Hitting the Brakes: Engineering Design and the Production of Knowledge (review)

In Hitting the Brakes, Ann Johnson offers a needed exploration into the theory and practice of engineering design. Academics often take this story for granted, assuming that engineers produce knowledge in the same fashion as scientists. However, using the development of antilock brakes, Johnson makes a convincing case that “engineering knowledge is a genuine kind of knowledge” deserving of its own theoretical analysis (p. ix). As Johnson reveals, engineering design is a complicated, organically evolving process.

Avoiding overly simplistic accounts of progress, Johnson cautions historians to examine the failures as well as successes in design. To produce antilock brakes, engineers from a variety of disciplines, government agencies, and corporations had to organize around a common problem and develop a common language. To describe how these actors organized and shifted, Johnson employs the concept of a “knowledge community . . . a small, informal community of practitioners that aggregates around a simultaneously developing question” (p. ixx). As the questions changed, so did membership in the communities. Most surprising to Johnson, she found that engineers had freedom to share information in formal and informal ways within their circles with little concern of violating corporate secrecy.

To highlight the complexity of the story, Johnson organizes her chapters thematically. The first and perhaps most interesting chapter establishes the definition of a knowledge community and its theoretical underpinnings. She emphasizes that engineering knowledge is produced through interactions among individuals, machines, measurements, and theory. These interactions are embodied in knowledge communities that often defied the expected boundaries of discipline, corporate fealty, and even individual training. Her framework makes the “human vectors of ideas” as important as the machines. The second chapter provides the basic narrative of the development of antilock brakes, tracing the contours of four distinct knowledge communities. Each community marks a different period spanning from the initial national interest in automobile safety in the 1950s and 1960s to the difficulties the knowledge communities faced when antilock brakes entered the market.

The remaining chapters deal thematically with the difficulties of design. Post–World War II England maintained the most accurate statistics on traffic accidents, enabling them to identify skidding as a problem. The government-supported British Road Research Laboratory (RRL) brought together the initial knowledge communities who defined skidding as an “interaction between the road, tyre, vehicle and driver” (p. 1). Unsure of where to focus their efforts, engineers at the RRL simultaneously explored all four aspects. Antiskid devices emerged as the most promising solution, in part because they held out the hope for a technological fix that did not require the driver’s active participation. The fourth chapter looks at the problem of metrology, or the science of measurement. This chapter is particularly strong, outlining the difficulties of measuring qualitative aspects such as “handling.” Next is an exploration of the pressure to mathematize vehicle dynamics and design models to make the study of driving more manageable, a promise that never came to fruition.

Chapters 6 and 7 examine the introduction of antilock brakes, focusing first on United States models beginning in 1966, and then on the second generation in the 1970s. Johnson attributes the failure of the first generation in part to American car companies’ unwillingness to share information. The eighth and final chapter explores what Johnson calls the “contradiction of public proprietary knowledge” (p. xiii). She concludes that the sharing of knowledge within the intimate confines of the community helped establish engineering as a profession while simultaneously promoting the production of new products, thereby benefiting corporations. John-son includes an interesting epilogue on the legacy of antilock brakes and their relationship to risk. In it, she argues that the hope of eliminating the driver from the skidding problem was never fulfilled.

Overall, this work is thought-provoking and a great addition to the history of technology, engineering, and automobile safety. The book did leave open, however, some important questions I hope other researchers explore. We learn little of...