Pioneer Hugh Dehaven revolutionized safety design by identifying the 'second collision'—the occupant hitting the vehicle's interior—as the primary cause of injury, not the initial impact. This paradigm shift moved engineering focus from making cars indestructible to making interiors survivable with features like seatbelts, airbags, and collapsible steering wheels.
When engineers modified the Golden Gate Bridge's railings, they tested the design in a wind tunnel to ensure structural integrity (wind load). However, this isolated test missed the acoustic effects. In the real world, the change turned the bridge into a massive musical instrument, demonstrating that even rigorous testing can fail to predict emergent properties of a complex system.
For connected products like Apple's AirTag, traditional testing for functionality and accidental misuse is insufficient. A critical new dimension is testing for intentional, malicious use, such as stalking. This requires product teams to adopt an adversarial mindset and build safeguards against ways their products could be weaponized by bad actors.
Effective testing struggles with a core tension. Standardized tests (like using chickens in jet engines) offer repeatability but lack real-world accuracy. Conversely, realistic tests (using grizzly bears on canisters) are authentic but hard to standardize. The best approach often finds a pragmatic balance between these two extremes.
Product safety engineering, or 'foolproofing,' extends beyond a product's intended function. It involves anticipating and designing for common, albeit incorrect, user behaviors. For example, a screwdriver must be robust enough to pry open a paint can, as this is a widespread and predictable misuse that designers must account for to prevent injury.
The SawStop table saw, which prevents severe finger injuries, is demonstrably safer than conventional saws. However, its higher cost led manufacturers to reject it. This forced the inventor to create a new, expensive product line, resulting in a two-tiered market where only risk-averse institutions (like schools) and wealthy hobbyists adopt the safer technology.
Instead of building ever-stronger structures to prevent failure (like taller levees), a more resilient approach accepts failure as inevitable. The Dutch 'Room for the River' project exemplifies this by designing systems to manage flood damage rather than trying to prevent it entirely, which involves complex societal negotiation and planning for impact.