This study used naturalistic driving data sets to examine whether driver adaptation took place when drivers of light vehicles and commercial motor vehicles were talking on a cell phone. The data set was based on naturalistic driving data from 204 drivers who each took part in the study for 31 days (on average) from February 2011 to November 2011. Data acquisition systems were installed in the vehicles owned by the participants. To examine whether talking on a cell phone impacted driving, a baseline epoch was sampled 30 seconds prior to the start of the first visual-manual cell phone subtask that was contiguous to the sampled call (e.g., reaching for the cell phone, dialing a number).
The mean age of participants was 41 years, and the majority (63%) were females. Of the 204 drivers, 191 provided their cell phone records (94%). Phone records were cross-referenced with driving data to confirm whether a participant was driving during the time of the phone call. This cross-check determined that 187 drivers (92%) had calls placed or received while their vehicles were in operation (N=14,754).
Results indicated that driver headway to a lead vehicle did not differ despite commercial motor vehicles drivers significantly increasing their speeds by 4 km/h (2.5 mph) when talking on a cell phone. However, commercial motor vehicles drivers changed lanes significantly less and light-vehicle drivers unintentionally departed their lanes significantly less when talking on a cell phone. Overall, the observed performance changes were not substantial.
Fitch, G. M., Grove, K., Hanowski, R. J., & Perez, M. A. (2014). Compensatory behavior of drivers when conversing on a cell phone: Investigation with naturalistic driving data. Transportation research record, 2434(1), 1-8.