If you are on the type of diabetes medication that has a significant risk of causing a low blood sugar, you should check your fingerstick glucose before driving. If your blood sugar is low, you should treat the low blood sugar much as you treat a low blood sugar reaction in general, for example, by eating a snack providing a readily available source of calories and then rechecking your blood sugar 20–30 minutes later. If you cannot delay your trip, take a snack and an ongoing source of sugar, such as Life Savers or other type of hard candy, that you can consume over time. You should make sure that you have a snack with readily available sugar in the car at all times. When driving, it is strongly recommended that you stop every 2 hours and check your blood sugar and eat your normally scheduled meals and snacks. Do not use your glucose meter while you are driving! You need to pull over and do the test while parked.
Remember that your vehicle is a very heavy object traveling at high speed and, when out of control even for only short periods, can be highly dangerous not only to you, but others around you. Also recall that other factors that contribute to inattention and loss of control can be additive to the danger of low blood sugar while driving. These include fatigue and lack of sleep, alcohol and other drugs (prescription or recreational), physical illness, and mental stress.