Idaho Road Signs Practice key terms

A sign that tells drivers what they must do or must not do, such as a stop, yield, speed limit, or turn restriction. Regulatory signs are usually white with black or red markings and carry legal weight.

A white rectangular regulatory sign with black numerals showing the maximum lawful speed in miles per hour. Unless otherwise posted, Idaho's default limit on rural interstate highways is 80 mph and on other highways 65 mph.

A red octagon with white letters reading STOP. A driver must come to a complete halt at the stop line, crosswalk, or edge of the intersecting roadway before proceeding when the way is clear.

A red-and-white downward-pointing triangle meaning the driver must slow or stop as needed to let traffic on the intersecting road or ramp go first. Stopping is required only when traffic is present.

An intersection where every approach has a stop sign. Vehicles arriving at the same time yield to the vehicle on the right, and any vehicle already stopped and waiting goes first.

A yellow diamond sign that alerts drivers to a change in road conditions ahead, such as a curve, hill, intersection, or narrowing lane. Warning signs do not create rules but tell drivers to slow or be alert.

A small yellow rectangular sign mounted below a warning sign giving the recommended maximum speed for the hazard, such as 25 MPH through a sharp curve. It is a suggestion, not a legal limit.

A yellow rectangular sign with a black arrow-shaped chevron used through sharp curves to show the direction of the turn. Drivers should follow the chevrons rather than cutting across lanes.

A yellow warning sign showing an arrow joining a through lane, telling drivers that traffic from a ramp or side road will enter their lane. Drivers already on the main road should adjust speed and space.

A yellow diamond warning sign showing a truck or a sloped grade, placed before steep descents. It warns that vehicles may slow down and that braking distance increases on the slope.

A sign marking an emergency escape ramp of gravel or sand for trucks that lose braking on a steep downgrade. Other drivers should keep the ramp clear and never park in it.

A sign that gives directions, distances, destinations, or services rather than rules. Guide signs are typically green for routes and destinations, blue for services, and brown for recreation and points of interest.

The red, white, and blue shield-shaped marker identifying an Interstate highway. Even-numbered routes generally run east-west and odd-numbered routes north-south, with higher numbers tending to lie farther north or east.

A small green sign along a highway showing the distance in miles from the state line or route origin. Drivers can use the number to report their location in an emergency.

A blue guide sign listing nearby amenities such as gas, food, lodging, or a hospital. These signs help drivers plan stops and do not impose any driving requirement.

A brown guide sign pointing to parks, campgrounds, historic sites, or other points of interest. Brown is reserved for recreation and cultural areas so drivers can spot them quickly.

A signal light controlling traffic at an intersection or ramp. A steady red means stop, steady green means proceed when clear, and a steady yellow warns that the light is about to turn red.

A signal arrow that flashes yellow, meaning a driver may turn in that direction after yielding to oncoming traffic and pedestrians. It is not a protected turn.

A left turn made on a steady green arrow, during which oncoming traffic is stopped. The driver may turn without yielding to opposing vehicles but must still watch for pedestrians.

After stopping completely at a red light, a driver may turn right unless a sign prohibits it, yielding first to pedestrians and cross traffic. Idaho also allows a left turn on red from a one-way street onto another one-way street.

Painted lines and symbols on the road surface that guide and regulate traffic. Yellow lines separate traffic moving in opposite directions, and white lines separate lanes moving the same way or mark the road edge.

Two solid yellow lines in the center of the road meaning passing is prohibited in both directions. A single broken yellow line allows passing when it is safe and legal.

A solid white line painted across a lane at an intersection or crosswalk. Drivers must stop before this line at a stop sign or red light so pedestrians and cross traffic have room.

A marked path for pedestrians across a roadway, shown by parallel white lines or a ladder pattern. Drivers must yield to pedestrians in a crosswalk, and passing a vehicle stopped at one is dangerous.

An orange diamond sign warning of construction, maintenance, or workers ahead. Orange is the color for temporary traffic control, and drivers should slow down and expect lane changes or flaggers.

An orange warning sign showing a worker holding a flag, placed before a point where a person controls traffic with a paddle or flag. Drivers must obey the flagger's signals, which override signs and signals.

An orange or black-on-yellow sign directing traffic along an alternate route around a closed road or work zone. Drivers should follow the detour markers rather than improvising a path.

A cone, drum, barricade, or tubular marker used to guide traffic around or away from a work zone. Drivers must not cross these devices or drive into a closed lane.

A yellow circular sign with a black X and two R letters marking a railroad crossing ahead. Drivers should slow, look both ways, and never stop on the tracks.

A white X-shaped sign with black letters reading RAILROAD CROSSING, posted at the tracks themselves. It means yield to trains, which always have the right of way.

Flashing red lights, bells, and gates at a railroad crossing. A driver must stop when the lights flash or the gate lowers and must never drive around a lowered gate.

A yellow-green pentagon-shaped sign marking a school area, often paired with a reduced speed limit when children are present. Drivers must slow to the posted school speed and watch for children.

A sign posting a lower speed limit in a school zone, sometimes with flashing beacons during arrival and dismissal hours. The reduced limit applies when the beacons flash or when children are present.

The eight-sided shape used only for STOP signs. Because no other sign shares it, drivers can recognize a stop from the shape alone even when the sign is dirty or partly blocked.

The downward-pointing triangle shape used only for YIELD signs. Like the octagon, it is reserved for one meaning so drivers can identify it by silhouette.

The four-sided diamond shape used for warning signs, almost always yellow with black symbols. Seeing a diamond tells a driver to expect a hazard rather than a rule.

The five-sided shape used for school zone and school crossing signs, colored yellow-green. It signals that children may be nearby and that a lower speed may apply.

Red on a sign means stop, yield, or prohibition, as on stop signs, yield signs, and do-not-enter signs. Red always calls for the most immediate driver action.

Orange marks temporary traffic control in work zones, including construction warnings, detours, and flagger signs. Orange tells drivers that normal road rules may be temporarily changed.

Yellow marks general warning signs about road conditions ahead, such as curves, hills, and intersections. A yellow sign means slow down and be prepared, not that a law has changed.

Green marks guide signs showing destinations, distances, exits, and mile markers. Green signs help with navigation and do not impose driving requirements.