Washington Driver Guide Vocabulary

A collection of vocabulary terms and definitions based on the Washington Driver Guide, covering licensing, vehicle mechanics, driving laws, and safety protocols.

Intermediate Driver License

A restricted license for teens ages 16 and 17 that includes limitations on passengers and nighttime driving.

Blood Alcohol Concentration (BAC)

A measurement of alcohol in the system; for drivers age 21 and older, the legal limit is $0.08\%$ or higher, and for those under 21, it is $0.02\%$.

THC Cannabis Concentration

A measurement of THC in the system; for drivers 21 and older, the limit is $5.00\,ng$ per milliliter of blood, while for those under 21, it is anything above $0.00\,ng$.

Open Container Law

A law prohibiting the consumption of alcohol/cannabis or the possession of open containers of these substances in the passenger compartment of a vehicle.

Tire Tread

The depth of the grooves on a tire; Washington law requires it to be no less than $2/32$ of an inch.

Antilock Braking System (ABS)

A safety feature that prevents wheels from locking during emergency braking, allowing the driver to maintain steering control.

Sharrows

Road markings indicating that a vehicle lane is shared with bicycle traffic.

Bicycle Boxes

Painted areas at intersections that allow bicyclists to position themselves in front of vehicles while waiting for a green light.

Roundabout

A circular intersection designed for all users where approaching vehicles yield to traffic already in the circle.

Diverging Diamond

An intersection design where traffic crosses to the left side of the roadway to improve the efficiency of left turns onto freeway ramps.

HOV Lane

High Occupancy Vehicle lanes reserved for carpools, vanpools, buses, and motorcycles.

Hydroplaning

A condition where water builds up between the tires and the road surface, causing the vehicle to lose traction and skid.

Black Ice

A thin, nearly invisible coating of ice on the roadway that is extremely treacherous for drivers.