Conference Proceeding

Driver Workload Management During Cell Phone Conversations Chip Wood,

  • Joshua Hurwitz (Motorola Labs, Tempe, AZ)
  • Chip Wood (Motorola Labs, Tempe, AZ)


This study tested if intelligently suspending cell phone conversationsduring demanding driving situations would improve driver’s performance andlessen subjective workload. Using a simulator, drivers followed a lead carapproximately 2 secs ahead and braking randomly. The drivers engaged inspontaneous “Neutral,” “Intense,” or “No” cell phone conversations with theexperimenter, who sustained all conversations with scripted non-directiveutterances. When the lead car started to decelerate, the conversations weresuspended or not for the duration of the event. Objective driving performance andsubjective “workload” estimates showed significant differences betweenconversation topic types. Engaging in an “Intense” conversation duringdeceleration produced (1) smaller decreases in forward velocity, and (2) delays inreleasing the accelerator, applying the brake and decelerating. Suspending“Intense” conversations counteracted these effects, producing larger decreases inforward velocity, and speeding up drivers’ responses on the vehicle controls.Furthermore, suspending conversations clearly increased drivers’ headways andtemporal distances with the lead car. The results show that cell phoneconversation intensity has significant effects on both performance and workload.The results also show positive effects of suspending cell phone conversationsduring critical driving situations on driver performance, thus perhapscounteracting the negative effects of the workload imposed by the conversations.Subjective ratings and value judgments for this system indicate generally positiveassessments of the system.

How to Cite:

Hurwitz, J. & Wood, C., (2005) “Driver Workload Management During Cell Phone Conversations Chip Wood,”, Driving Assessment Conference 3(2005), 202-209. doi:

Rights: Copyright © 2005 the author(s)

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Published on
28 Jun 2005
Peer Reviewed