Task	No difficulty	A little difficulty	Moderate difficulty	Extreme difficulty	Stopped due to eyesight	Stopped due to other reasons
How much difficulty do you have driving during the daytime in familiar places?	1	2	3	4	NA	NA
How much difficulty do you have driving at night?	1	2	3	4	5	6
How much difficulty do you have driving in difficult conditions, such as in bad weather, during rush hour, on the freeway, or in city traffic?	1	2	3	4	5	6