Traffic Vocabulary and Definitions The funny thing about driving your car off a cliff, I bet you're still hitting those brakes. – Jack Handey

Absolute Speed Limit The maximum or minimum posted speed at which one may drive under normal conditions in good weather.

Acceleration Lane A lane used by drivers entering the expressway to pick up speed so they can merge with expressway traffic.

Accelerator Pedal Controls the flow of fuel to the engine and regulates speed.

Actual Physical Control A person can be charged with DUI of alcohol or some other drug if they have the ability to move their vehicle.

Advisory Speed Limit A speed limit that advises drivers that an adjusted speed is necessary for a short period of time.

Anti-lock Braking Systems (ABS) A vehicle braking system that is designed to keep a vehicle’s wheel from locking when brakes are applied with greater than normal force.

Basic Speed Law Any speed under the absolute limit that is safe for existing road, weather, or traffic conditions.

Blind Spot Areas to the sides and rear of the vehicle that the driver cannot see with the use of either side or rear view mirrors.

Blood Alcohol Concentration (BAC) The percentage of alcohol found in a person’s blood at any given time. In addition, BAC is how law enforcement measures the level of intoxication in a person. (Alabama BAC limit for underage persons .02%, 21 and older .08%)

Carbon Monoxide A highly poisonous gas that is given off by burning fossil fuel. It is colorless and odorless. Note: Many people die each year from breathing this gas. Most are teens or young adults sitting in parked vehicles.

Centrifugal Force A natural law that tends to push a vehicle out of a curve and into a straight path.

Contrast Sensitivity The ability to see under difficult conditions such as glare from oncoming headlights, heavy snow conditions, and even driving at night.

Cover the Brake Take your foot off the accelerator and hold it over the brake pedal to be ready to brake quickly.

Driving Under the Influence (DUI) Driving under the influence of any mind altering drug. This includes alcohol, prescription and non-prescription drugs, marijuana, hallucinogenic drugs, and any other drugs that alter the brain. In Alabama you can be arrested and taken to jail for a BAC of .05% even when the legal limit for adults (21 and over) is .08%

Fresh/ Stale Green Light Fresh Green Light- light has just turned from red to green Stale Green Light- light that has been green for a long time

Hand Position Refers to hand placement on the steering wheel while driving Hand-over-hand steering– method where hands cross over each other while turning Push-pull-feed steering– method where hands do not cross while turning (used with airbags) “9 and 3” or “10 and 2”– refers to hand placement while driving

Highway Hypnosis A trance-like state of drowsiness that can occur with little warning, usually occurs after long hours behind the wheel caused by concentration on the road ahead and the monotony of driving To fight highway hypnosis it is recommended to stop and walk around your vehicle every 100 miles or 2 hours.

Hydroplaning Condition in which the tires of a moving vehicle ride on a cushion of water causing loss of control in both steering and braking

Implied Consent The law stating that any licensed driver cannot legally refuse to be tested for alcohol or drug use while behind the wheel or in “actual physical control” of a vehicle. You give consent when you sign your license

Overdrive At speeds of 40-45 mph the vehicle automatically shifts into overdrive. Driving in this gear saves fuel and can be used for all normal driving conditions.

Over-driving your headlights Driving so fast at night that a driver is unable to stop within the range of their headlights

SIPDE The basic principles of defensive driving. The letters stand for:

Space Margin A cushion of space a driver tries to maintain around their vehicle. Space margin distance increases as speed goes up. Note: A safe following distance for good weather is about two (2) seconds behind the vehicle in front of you. As the weather becomes worse, your space margin should increase.

Stop Bar The white line painted on the road where a stop is required. They are most commonly found at intersections. DO NOT CROSS

Total Stopping Distance The distance to bring a vehicle to a complete stop from the time of perception until the wheels actually stop rolling. Note: At 60 mph a vehicle equipped with good tires and brakes travels almost 300 feet from the time you see the conflict until you actually bring the vehicle to a stop.

Uncontrolled Stop Usually in a neighborhood, this is where a stop is required but there is no sign.

Velocitizing The sensation of moving more slowly than one actually is as a result of driving at a fast speed for a long period of time. Example: Leaving the freeway and moving to a surface street with a speed limit of 35 mph. As a result traveling at the speed limit may seem much slower.