Table 1. Mean and Distribution of Driving Exposure Measures During the Learner Permit Period (n=90).

Driving Exposure Measure	Mean	Standard Deviation	25th Percentile	50th Percentile	75th Percentile
						Total Months	10.64	2.83	9.13	9.20	10.83
Total Trips	207.62	141.13	97.00	192.00	275.00
Total Miles	1219.06	920.19	502.39	104 000	1637.59
Total Miles at Night	263.38	300.42	61.78	159.95	332.77
Total Miles in Wet Conditions	127.52	112.72	46.59	92.18	170.57
Total Hours	46.56	32.28	24.39	40.39	61.58
Total Hours at Night	10.07	10.18	3.34	6.97	13.49
Total Hours in Wet Conditions	5.15	4.16	2.47	4.10	7.10
Average Single Trip (miles)	5.89	2.45	4.15	5.63	7.32
Average Single Trip (minutes)	13.68	3.61	11.49	13.37	15.86