. Author manuscript; available in PMC: 2016 Jun 1.

Published in final edited form as: Accid Anal Prev. 2016 Mar 5;91:55–63. doi: 10.1016/j.aap.2016.02.027

Table 3.

Driver demographic characteristics by sleep pattern clusters.

Cluster	# of Drivers	# of Shifts	% Shifts	By shifts
Cluster	# of Drivers	# of Shifts	% Shifts	Average age^*	% Male^*	Average BMI^*	Average years of commercial vehicle driving^*
1	66	250	18	46.9	92.4	32.3	10.5
2	31	86	6	42.7	97.7	30.9	10.6
3	81	544	39	45.1	96.7	31.7	9.5
4	66	517	37	43.1	89.6	32.0	6.8

Averages are calculated based on shifts, not individual driver.