Table 3.

Frequency of observed driver distractions.

Code in Appendix A	Observed driver distractions	Frequency
OTCOG	other cognitive tasks (minimal manual or visual effort), e.g. n-back task, sound counting	44
ADSG	roadside advertising signs, billboards, information or logo signs, regardless of type (static, electronic, video...)	23
OTVIS	other visual tasks (minimal cognitive or manual effort), e.g. target search	18
PHCNV_h	hand-held cell phone conversation	17
PHDIA_h	hand-held cell phone dialling task	15
IVIS	in-vehicle information system or driver support systems, e.g. driving support and information, various control features	15
NAV_iv	in-vehicle navigation system	14
RADMS	radio or in-vehicle built in music system use, e.g. radio tuning, CD change, music search	14
OTTE	other elements of the traffic environment, e.g. pedestrians	14
PHCNV_hf	cell phone conversation using a hands-free system	9
NAV_ptb	portable navigation system	8
PHOTH	other cell phone/smartphone tasks, e.g. browsing social networks, app use	7
IVPAR	adjusting or reading various in-vehicle parameters, such as climate control, lights, speed control	6
PMP	portable music player	5
PHTXT	sending and receiving SMS messages via cell phone (texting)	5
OTMAN	other manual tasks, e.g. in-vehicle search tasks	5
PHDIA_hf	cell phone dialling task using a hands-free system	4
OTIV	other elements inside the vehicle	4
PASS	passenger	3