Dario Salvucci
Department of Computer Science, Drexel University
Home Research Publications Teaching Media Biography


My research lies at the intersection of computer science and psychology. My work primarily focuses on multitasking and interruption in complex domains, such as driver distraction and human-computer interaction, using computational cognitive models to simulate human behavior. Please click on the tabs below for more information about each topic.

Multitasking & Interruption Driver Distraction Cognitive Modeling
How do people drive, cognitively speaking?
When steering a car, drivers rapidly scan two distinct visual areas: the lane directly in front of them to keep the car centered, and the lane in the distance to guide smooth steering especially around curves. This information is used to adjust the steering wheel and, when another car is in front, adjust the car's speed as well. We have developed a computational model of steering and lane changing that demonstrates how people can adjust steering roughly 4-5 times per second -- typically adequate for normal driving, but when distracting tasks interrupt these adjustments, performance can quickly degrade.
How does cell-phone dialing affect driving?
There have been a number of studies showing the negative effects of cell-phone dialing (and conversation) on driving performance. In our own study, we found that manually dialing a phone (by pressing keys) was significantly more distracting than voice dialing, leading to an decreased ability to keep the car centered in the lane. Dialing using an address book-style menu also degrades driving. These effects are present for hands-free devices mounted on the dashboard; thus, our studies have agreed with previous studies in that hands-free and handheld phones can both be distracting.
How does iPod use affect driving?
A recent GMAC survey reported that 20% of drivers age 18-24 have used an iPod while driving. Knowing how distracting cell phones can be, it may not be surprising that using an iPod while driving can also be distracting. More surprising is the size of the effect. Our study of iPod distraction found that selecting a song on an iPod can degrade performance almost twice as much as dialing a cell phone. Even more surprisingly, selecting a song can degrade performance twice as much as watching a video on the iPod. The level of distraction for iPod use is severe and warrants further consideration as an important source of driver distraction.
Can just thinking about something affect driving?
Yes! We ran a laboratory study in which people simply memorized a list of numbers, similar to trying to remember items to buy at a grocery store or directions to a new location. Drivers only had to think about this list while driving, and yet they exhibited a 50-millisecond slowdown in their brake reaction times (for a 9-item list). While 50 milliseconds may not seem like much, consider that a car on a highway can travel about 10 feet in that short time, potentially being the difference between a crash and a near-miss.
How can we predict the distraction potential of new devices?
Many areas of engineering have tools at their disposal for making predictions about new devices and machines, such as design systems for automobiles or planes that can predict wind resistance, drag, lift, etc. before the vehicle is actually built. Such tools have been difficult to come by for predictions of cognition and behavior. However, we have developed an initial system called Distract-R in which a design can specify a prototype of a new in-vehicle device, like a new radio interface or cell-phone dialing technique. The system uses a model of driver behavior to predict the distraction potential of this new device based on common measures of driver performance. Our hope is that this system can facilitate rapid prototyping of many possible devices and pare down the number to a few (say 2-4) devices that would then be developed and rigorously tested within real vehicles.