Drowsiness is trazodone's most common side effect, and it can impair reaction time and attention in ways relevant to driving safety — similar to concerns with many sedating medications. This is most pronounced early in treatment, after a dose increase, or the morning after a nighttime dose taken for sleep.
Don't drive until you know how trazodone affects you personally. If you take it at bedtime for sleep, pay attention to whether you feel fully alert the next morning, particularly at higher doses — and never combine it with alcohol before driving.