Blood alcohol concentration (BAC): A measure of weight by volume of alcohol in the blood, estimated via breath tests.
Distraction: Lack of concentration on the driving task, due to diversion of attention to activities inside or outside the vehicle, or cognitive factors, e.g. day dreaming.
Driver education: A formal course for teaching beginners how to drive, including basic driving skills, rules of the road, and recommended safety practices.
Fatigue: Basically tiredness, due to lack of sleep or other factors.
Graduated Driver License (GDL) program: A step-wise, systematic introduction to full licensing that imposes conditions on the driving privileges of novice drivers so that they gain experience and mature under low risk conditions.
GDL Framework: Overall scheme for GDL, incorporating essential GDL elements—extended learner period, night and passenger restrictions—and supporting elements, e.g. driver education, seat belt laws.
Impairment: A condition that interferes with the ability to drive safely.
Inexperience: Lack of practice driving, in terms of miles driven and exposure to a variety of real-life driving situations.
Intermediate (provisional) stage: The second stage of the graduated licensing program. During this stage, the driver can drive unsupervised but only under certain conditions – e.g., during daytime hours; with few or no passengers.
In-vehicle monitoring: Systems for indicating when risky driving practices have occurred (e.g., speeding), and transmitting this information to the teens who are driving and/or their parents.
Learner stage: The first/initial stage of the graduated licensing program. During this stage, the driver must be accompanied by a supervising driver.
Log book: A booklet that allows recording of trips taken during the learner phase, including type of trip, duration (hours, miles), and other pertinent details.
Novice driver: A novice driver is a new, inexperienced driver. This includes GDL learner and intermediate drivers as well as those who have bypassed GDL and are initially licensed to drive at an older age.
Risk factor: Any factor that increases crash risk for teenagers, such as driving late at night, or with same-age passengers.
Vehicle decal: A decal or other identifying sign in or on the vehicle, visible to other motorists, indicating that the driver is subject to GDL restrictions.