I’ve heard a great deal about trust and automation over the years, but this has to be my favorite new example of over-reliance on a system.
GPS routed bus under bridge, company says
“The driver of the bus carrying the Garfield High School girls softball team that hit a brick and concrete footbridge was using a GPS navigation system that routed the tall bus under the 9-foot bridge, the charter company’s president said Thursday.Steve Abegg, president of Journey Lines in Lynnwood, said the off-the-shelf navigation unit had settings for car, motorcycle, bus or truck. Although the unit was set for a bus, it chose a route through the Washington Park Arboretum that did not provide enough clearance for the nearly 12-foot-high vehicle, Abegg said. The driver told police he did not see the flashing lights or yellow sign posting the bridge height.
“We haven’t really had serious problems with anything, but here it’s presented a problem that we didn’t consider,” Abegg said of the GPS unit. “We just thought it would be a safe route because, why else would they have a selection for a bus?””
Link to original story (with pictures of sheared bus and bridge)
Indeed, why WOULD “they” have a selection for a bus? Here is an excerpt from the manual (Disclosure: I am assuming it’s the same model):
“Calculate Routes for – Lets you take full advantage of the routing information built in the City Navigator maps. Some roads have vehicle-based restrictions. For example, a street or gate may be accessible by emergency vehicles only, or a residential street may not allow commercial trucking traffic. By specifying which vehicle type you are driving, you can avoid being routed through an area that is prohibited for your type of vehicle. Likewise, the ******** III may give you access to roads or turns that wouldn’t be available to normal traffic. The following options are available:
- Truck (large semi-tractor/trailer
- Emergency (ambulance, fire department, police, etc.)
- Delivery (delivery vehicles)
- Bicycle (avoids routing through interstates and major highways)
If we can assume no automation can be 100% reliable, at what point to people put too much trust in the system? At what point do they ignore the system in favor of more difficult methods, such as a paper map?At what point is a system so misleading that it should not be offered at all? Sanchez (2006) addressed this question and related type and timing of error to amount of trust placed in the automation. Trust declined sharply (for a time) after an error, so we may assume the Seattle driver might have re-checked the route manually had other (less catastrophic) errors occurred in the past.*
The spokesman for the GPS company is quoted in the above article as stating:
“Stoplights aren’t in our databases, either, but you’re still expected to stop for stoplights.”
I didn’t read the whole manual, but I’m pretty sure it doesn’t say the GPS would warn you of stoplights, a closer analogy to the actual feature that contributed to the accident. This is a time where an apology and a promise of re-design might serve the company better than blaming their users.
*Not a good strategy for preventing accidents!
Other sources for information on trust and reliability of automated systems:
Lee, J.D. & See, K.A. (2004). Trust in Automation: Designing for Appropriate Reliance. Human Factors, 46, 50-80.
Parasuraman, R. & Riley, V. (1997). Humans and automation: use, misuse, disuse, abuse. Human Factors, 39, 230-253.
Wiegmann, D. A., Rich, A., Zhang, H. (2001). Automated diagnostic aids: the effects of aid reliability on users’ trust and reliance. Theoretical Issues in Ergonomics Science, 2(4), 352-367.
The Cognitive Engineering Laboratory