Signs, Signals and Road Markings: Sign Shapes and Colors, Regulatory Signs From the Four-Way Stop to Speed Limit, Minimum Speed and No Turn on Red, Warning Signs From Sharp Turns to Cattle Crossings, School, Pedestrian and Bicycle Signs, Work Zone Signs and Arrow Panels, Guide, Service and Route Signs, Mileposts, Centerlines, Lane Dividers, Edge Lines, White Lines and Crosswalks, Traffic Signals and Arrows, Lane Use Control Signals, and Driving One- and Two-Lane Roundabouts

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

Source: Alabama Driver Manual (ALEA, November 2024 edition), Chapter 5 "Signs, Signals and Road Markings" (pages 41–58).

Shapes and colors

You must recognize signs instantly and obey regulatory ones without hesitation. Symbols and pictures allow quicker recognition at speed and distance, and both shape and color are coded to the message. The three types are regulatory, warning and informational or guide signs; the standard shapes mark the school warning, yield, no passing zone, warning, construction, slow-moving vehicle, stop, railroad warning, regulatory and guide signs.

Regulatory signs

Regulatory signs are black and white except those shown in color, and must be obeyed. At a four-way stop, vehicles leave in the order they arrived: the first to come to a complete stop goes first, and when several arrive together the one farthest to the right goes first; wait a few seconds to be sure no one else starts, even on your turn, because many drivers ignore the rule. The yield sign means slow down to give the right-of-way to pedestrians crossing and to vehicles on the intersecting road. Wrong Way, white on red, means you are entering a one-way highway or ramp against traffic; Do Not Enter marks a one-way road with traffic coming toward you. The railroad crossbuck means approach with caution and be sure every track is clear. No Left Turn forbids a left turn at that intersection; No Parking means you may not park even while staying in the car; Reserved Parking for a handicap plate or permit may not be used on private or public property unless the vehicle is operated by or under the direction of a physically handicapped person and displays the sticker; Emergency Stopping Only allows stops only for real emergencies; Left Lane Must Turn Left binds traffic in that lane; No Turns bars both right and left turns. Speed Limit gives the limit under normal conditions; a combined Speed Limit 55 / Minimum 45 sign gives the maximum and minimum for that stretch, minimums being usual on freeways and controlled-access highways; a 30 sign is the top speed in that area; the school zone limit applies during the hours shown and may appear on a lighted sign with flashing amber lights. Do Not Pass marks the start of a no-passing zone; No Turn on Red forbids right or left turns on red where posted; Keep Right means do not drive left of the sign; a lane-use sign with "Only" means the right lane must turn right while the next lane may turn or go straight, and double right turns are allowed only where signed; an arrow sign allows travel only in that direction; and Divided Highway signs mark divided roads.

Warning signs

Warning signs are black on yellow, or black on orange in construction areas, and warn of hazards needing extra caution; fluorescent yellow marks pedestrian crossings and school zones; most are diamonds. They include a sharp turn left, a curve right, a gradual curve right then left, a winding road, a side road entering from the right or at an angle, Bump (slow down), a T-junction where you must turn right or left, Soft Shoulder (do not drive off the pavement), Road Narrows, an island you may pass on either side, Dip (slow down), a sharp left then sharp right, a road that turns both ways, One Lane Bridge (no room to meet or pass), Stop Ahead, Yield Ahead, Pavement Narrows, an advisory speed plate giving the top safe speed for a turn, chevron arrows placed in series at sharp turns, the round railroad advance sign (slow, look both ways, be ready to stop; a train cannot stop quickly), a low shoulder, Truck Crossing, Fire Station, Pavement Ends (gravel or dirt ahead), Dead End, the series Lane Ends / Merge Left / Right Lane Ends as a repeating reminder to merge, the No Passing Zone pennant on the left side of a two-lane road, a signal ahead, a low-clearance sign giving the height limit, a two-way traffic sign where a one-way road becomes two-way, a merge sign where entering drivers on the right must yield and use the speed-change lane, a crossroad, divided highway begins and ends, a downhill grade, slippery when wet, narrow bridge, cattle crossing, deer crossing, a pedestrian crossing (yield to people in the crosswalk, which may not be at an intersection), school crossing, school bus stop ahead and bike crossing (both the older and newer colors are in use), a 3-foot minimum passing clearance sign, a bicycles may use full lane sign for narrow lanes, and sharrows painted on the pavement to show that bicyclists may occupy the lane.

Work zone signs

Road Construction 1500 Ft means you are entering a construction area: watch for flaggers, one-way traffic, other signs and obstructions, and obey signs and instructions. Other signs show a flagger ahead, workers in or near the road and Mowers Ahead. Large flashing or sequencing arrow panels, day and night, steer drivers into certain lanes and show that part of the road ahead is closed.

Guide signs, routes and mileposts

Guide signs are green and white for directions, blue and white for services such as hospital and gas-food-lodging, and brown and white for recreational and cultural points such as a state park; route markers for interstate, US, state and county routes appear in their real colors. Mileposts stand along most main highways to pinpoint locations for emergencies and maintenance, with mileage starting at the south and west state lines or where a route begins.

Pavement markings

The four types are centerlines, edge lines, crosswalks and pavement messages. The centerline separates opposing traffic and is yellow on two-lane highways and white on multi-lane highways and one-way streets; broken lines allow passing when safe, a solid yellow line beside the broken line means no passing for the side it is on, and where neither direction may pass the broken line becomes two solid yellow lines. Lane dividers on roads with two or more lanes one way are broken white lines that may be crossed when passing. Edge lines are solid white at the right or left edge and may be crossed only by traffic moving to or from the shoulder; yellow left edge lines appear on divided roads where traffic cannot leave the roadway and on obstructions and islands that must be passed on the right. A normal solid white line between same-direction lanes discourages crossing, a wide one marks where crossing needs unusual care, and double solid white lines prohibit crossing. Crosswalks are solid white lines at intersections and sometimes between them, and a driver must stop at any crosswalk occupied by a pedestrian where there is no signal. Pavement messages such as SCHOOL ZONE and RR CROSSING are lettered in white. On a two-lane two-way road passing may be permitted, prohibited in one direction, or prohibited both ways with the center line crossed only to turn left; on a multi-lane two-way road the centerline is crossed only to turn left; a two-way left-turn lane is reserved for left turns from either direction; and a divided road has a non-traversable divider.

Traffic signals

Red (steady circular): stop and remain stopped until green; right turns, and in certain cases left turns, are allowed after stopping. Yellow (steady circular): clear the intersection; it follows green, and you must not enter when red comes on. Green: go straight or turn right or left, yielding to vehicles and pedestrians lawfully in the intersection, unless a sign prohibits the turn. Red flashing lights with crossbucks at railroad crossings mean stop when they begin to flash and do not proceed until safe, checking every track; gates at some crossings lower after the lights begin, and you stay stopped until they rise and the lights stop. Arrows control specific turns and give left turns the same control a standard light gives through traffic: a green arrow lets you go in its direction while opposing traffic is stopped, alone or with another indication, yielding to pedestrians and vehicles lawfully in the intersection; a yellow arrow after a green arrow means the protected movement is ending, whether shown with a circular green, alone, or with a circular red, and you may not enter after the yellow arrow goes out. Lane use control signals over individual lanes: a steady red X means you may not drive in that lane; a steady green arrow allows it; a steady yellow X allows it with caution because hazardous conditions exist; each may also be shown by a plain red, green or yellow light.

Roundabouts

A roundabout is a circular intersection, usually unsignalized, flowing counterclockwise around a central island; enter from the right, yielding to traffic already circulating, and follow the circle to your road. Roundabouts cut fatal crashes about 90 percent, injury crashes about 75 percent and all crashes about 35 percent compared with other intersection controls, and the usual intersection rules apply. Slow down and obey the signs; before entering, yield to pedestrians and bicyclists; yield to traffic on your left already in the circle; enter on a safe gap; keep your speed low; turn onto your exit road; yield to pedestrians and bicycles as you leave; and if you miss your exit, go around again. Always yield to emergency vehicles: pull over before entering, or if already inside continue to your exit and then pull over, and avoid stopping in the circle. The truck apron is a paved ring inside the roundabout for the rear wheels of large trucks, not for cars, pickups or SUVs. Vehicles in the roundabout have the right-of-way, never turn left to enter, never stop inside unless it is the only way to avoid a crash, and never back up. In a two-lane roundabout choose your lane first and yield to traffic in both lanes: typically the right lane is for right turns or through traffic and the left lane for left turns, U-turns or through traffic, following the pavement arrows and black-and-white lane signs.

Practise this with Alabama Driver License questions

More of this guide