Frequency and impact of hands-free telephoning while driving – Results from naturalistic driving data

•Based on naturalistic driving data, frequency and impact of hands-free telephoning was analyzed.•The database contained about 3months of driving data for N=106 drivers.•On average, drivers talked on the phone during 11% of driving time.•During telephoning, speed was reduced and time-distance to the lead-vehicle was enlarged.•Overall, the relative risk for potentially critical situations was reduced during telephoning.