Signs and Traffic Signals: Red Prohibitive Signs From the Octagon to No U-Turn, White Regulatory Signs Including Right Turn Permitted Without Stopping, Transit-Only Lanes, Keep Right, Center Lane Turn Only, HOV, Left Turn Yield on Green and Stop Here for Pedestrians, Yellow Warning Signs for Crossings, Curves, Chevrons, Merges, Lane Reductions, Divided Highways, Stop and Signal Ahead, Roundabouts, Railroads, Low Clearance, Hills, Advisory Speeds, Slippery Roads and Deer, Route, Green Guide, Safety Corridor, Brown and Blue Signs, Dark Signals Treated as Four-Way Stops, Turns on Red, Flashing Red and Yellow, Red, Yellow and Green Arrows and the Flashing Yellow Arrow

Written for aiforu2 as the source for a practice-test bank and the on-device tutor for the Oregon Class C knowledge test. The facts follow the official manual; the wording is ours.

Source: Oregon Driver Manual 2026–2027 (ODOT DMV), "Signs & Traffic Signals" (pages 7–17).

Reading signs

Obey every official sign, signal and marking unless a police officer or road worker redirects traffic. Signs often use symbols rather than words, and each type has its own color and shape so you can recognize it at a glance.

Regulatory signs that prohibit

Signs that prohibit an action are red and control flow through intersections. The stop sign, an octagon, requires a complete stop; yield to other vehicles, stop and stay stopped for pedestrians in marked or unmarked crosswalks, and enter when safe. The yield sign, a triangle, means slow and give the right-of-way, stopping if needed as at a stop sign. Do Not Enter, a square, warns you off a road or freeway and appears when you are going the wrong way. No Left Turn, No Right Turn and No U-Turn, a red circle with a slash, forbid the turn shown.

Other regulatory signs

Other regulatory signs are rectangles with black words or symbols on white, posted where the requirement applies. Speed Limit gives the maximum in miles per hour, sometimes on an electronic sign that changes with conditions. One Way means traffic flows only with the arrow. Right Turn Permitted Without Stopping, below a stop sign, lets right-turning traffic continue while all other traffic stops and yields. Lane-use control signs show where turns are required or permitted from each lane. Right Lane Transit Only marks lanes where only transit vehicles, or bicycles if the sign says so, may continue straight through an intersection; Right Turns Permitted lets you briefly use the transit lane to turn into a driveway, turn at the next intersection or pull over to park where allowed, always yielding to transit vehicles and bicycles and merging behind them. Keep Right marks a traffic island, median or obstruction ahead. Center Lane Turn Only means the center lane is shared for left turns from both directions. Do Not Pass forbids passing. No Turn on Red means wait for green. High Occupancy Vehicle reserves a lane for vehicles carrying at least the number of people shown, sometimes marked by a white diamond on the pavement. Left Turn Yield on Green means yield to oncoming traffic and pedestrians on a circular green until the turn is safe. Stop Here for Pedestrians marks the stop line to use when a pedestrian is in the crosswalk.

Warning signs

Warning signs are yellow and alert you to known hazards or changing conditions, though you remain responsible for reacting to conditions whether signed or not. Pedestrian Crossing may carry a flashing yellow beacon meaning someone is crossing, has just crossed or is about to; Multiuse Path Crossing marks regular bicycle and pedestrian crossings; In-Street Pedestrian Crossing at a crosswalk means stop when a pedestrian is in it. Curve, Sharp Turn, Chevron (a sharp curve or change of direction at the sign), Winding Road and Reversing Curves (right, then left) warn of bends; Crossroad of a four-way intersection with cross traffic; Side Road of a T-intersection with traffic entering from left or right; Merge of traffic joining from the side shown; Add Lane of two roads joining without a merge; Lane Reduction of a lane ending, whose vehicles must merge into the through lane; Two-Way Traffic Ahead that a one-way road is joining a two-way road; Divided Highway Begins or Ends to keep right; Stop Ahead and Signal Ahead to slow and prepare to stop; Reduced Speed Limit Ahead to prepare to slow; Roundabout Ahead; Railroad Advance, a crossing ahead where you may have to stop; Low Clearance, not to proceed if your vehicle is too tall; Hill, a steep grade; Advisory Speed, the safe speed for ramps and curves, sometimes electronic and used with other signs; Slippery When Wet; and Deer, to be alert and slow down if you see wildlife.

Route, guide and information signs

Route signs show which route you are on and whether it is an interstate, US route or state highway. Guide or information signs are green, giving exit information and the direction of roads and cities; the number on an exit sign identifies the exit. Safety Corridor signs mark stretches with more fatal and serious-injury collisions than the state average, sometimes with diamond-shaped flags; turn on your lights there. Brown signs point to historic, cultural and recreational places such as scenic areas, picnic grounds and parks. Blue motorist service signs tell of gas, food, lodging, a rest area, an electric vehicle charging station, accessible facilities or parking, or the road to a hospital.

Traffic signals

Signals control the right-of-way and keep traffic orderly. A signal that is dark, as in a power failure, means stop as if there were stop signs in all directions; an out-of-order signal flashing yellow or red is obeyed as a flashing signal. Steady circular red: stop and stay stopped until the signal changes; after a complete stop, unless a sign or officer says otherwise, you may turn right when entering a two-way road, and right or left in the direction of travel when entering a one-way road. Flashing red or a dark signal is treated as a stop sign. Red arrow: stop and remain stopped until it changes, except for the same turns on red allowed at a steady red. Steady circular yellow: the signal is about to turn red; stop before entering, or if you cannot stop safely, drive carefully through. Flashing yellow: slow and proceed with caution. Steady yellow arrow: the same as a steady yellow, stop unless you cannot safely. Flashing yellow arrow: you may make the movement shown after yielding to pedestrians and oncoming traffic, which has a steady green. Steady circular green: all movements are permitted unless a sign prohibits one; a left turn first yields to pedestrians and oncoming traffic, and a right turn first yields to pedestrians. Steady green arrow: you have the right-of-way for the movement shown.

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