- Octagon-shaped sign
- Always a STOP sign — the only 8-sided sign. Come to a complete stop, yield, then go when it is safe.
- Downward-pointing triangle sign
- A YIELD sign. Slow down, give the right-of-way to other traffic and pedestrians, and stop if needed.
- Yellow diamond-shaped sign
- A general warning sign — a curve, hill, merge, or other hazard is ahead. Slow down and stay alert.
- Orange diamond-shaped sign
- A construction or work-zone warning. Slow down, watch for workers, and obey flaggers and lane shifts.
- Pentagon (5-sided) sign
- A school zone or school-crossing sign. Watch for children and be ready to slow to the school-zone limit.
- Pennant-shaped sign (horizontal triangle)
- A no-passing-zone warning, posted on the left side of the road. Do not pass beyond this point.
- Round (circular) sign
- A railroad-crossing advance warning. A train track crosses the road ahead — slow down and be ready to stop.
- Crossbuck sign
- The white X-shaped 'RAILROAD CROSSING' sign at the tracks. It means yield — give way to any approaching train.
- White rectangular sign
- A regulatory sign — it tells you a law you must obey (speed limit, one way, lane use, no turns).
- Red color on a sign
- Stop or prohibition (stop, yield, do not enter, wrong way, no turns).
- Yellow color on a sign
- A general warning of a hazard ahead (curve, intersection, slippery road, deer crossing).
- Orange color on a sign
- Construction and maintenance work zones — slow down and expect workers, equipment, and lane changes.
- Green color on a sign
- Guide and directional information — distances, destinations, exits, and street names.
- Blue color on a sign
- Motorist services — gas, food, lodging, hospitals, and rest areas.
- Brown color on a sign
- Recreation and points of interest — parks, campgrounds, historic and scenic sites.
- Steady red light
- Stop and stay stopped behind the line until the light turns green. A right turn on red is allowed in most states after a full stop, unless prohibited.
- Steady yellow light
- The light is about to turn red. Stop if you can do so safely; do not speed up to beat the light.
- Steady green light
- Go if the intersection is clear. When turning, you must still yield to oncoming traffic and pedestrians.
- Flashing red light
- Treat it exactly like a STOP sign: come to a complete stop, yield, then proceed when it is safe.
- Flashing yellow light
- A caution signal — slow down, stay alert, and proceed carefully through the intersection.
- Red arrow
- Stop — no turn in the direction of the arrow until it turns green, even if the way looks clear.
- Green arrow
- A protected movement in the direction of the arrow — you may go that way, and oncoming traffic is stopped.
- Completely dark traffic signal
- Treat the intersection as an all-way (four-way) stop — every direction stops and takes turns.
- Solid yellow line on your side
- No passing — do not cross it to pass. Yellow lines separate traffic moving in opposite directions.
- Broken (dashed) yellow line
- Passing is allowed when it is safe; the line still separates opposing directions of traffic.
- Double solid yellow lines
- No passing in either direction. You may cross only to turn into or out of a driveway when safe.
- Solid white line
- Discourages or prohibits lane changes — stay in your lane. White lines separate same-direction traffic.
- Broken (dashed) white line
- Separates lanes going the same direction; you may change lanes across it when it is safe.
- Two-way left-turn lane (center, yellow lines)
- A shared center lane for left turns only, used by traffic from both directions. Never use it to pass or travel.
- Stop line (white bar across the lane)
- Stop behind this line at a stop sign or red light. If there is no line, stop before the crosswalk.
- Crosswalk lines
- Mark where pedestrians cross. Stop before them and yield to anyone in or entering the crosswalk.
- Yield sign meaning
- Slow down, prepare to stop, and give the right-of-way to traffic and pedestrians before proceeding.
- Stop sign meaning
- Come to a complete stop at the line, yield to all cross traffic and pedestrians, then go when clear.
- Do Not Enter sign
- A white horizontal bar in a red circle — you may not enter; the roadway is one-way against you.
- Wrong Way sign
- You are traveling against traffic on a one-way road or ramp. Stop, then turn around safely.
- One Way sign
- Traffic moves only in the direction of the arrow on this street; never drive against it.
- No Turn on Red sign
- Overrides the usual right-on-red allowance — you may not turn on the red signal where it is posted.
- Speed Limit sign (white rectangle)
- A regulatory sign giving the maximum legal speed in good conditions; you must drive slower when needed.
- Slow Moving Vehicle emblem
- An orange-and-red reflective triangle on a vehicle that travels under 25 mph — slow down and pass with care.
- Roundabout / circular intersection warning
- A roundabout is ahead. Slow down, yield to traffic already circulating, and enter when there is a safe gap.
- Merge sign
- Two lanes of traffic are about to join. Adjust your speed and position to blend in smoothly and safely.
- Divided highway sign
- The road ahead splits into separate roadways by a median. Keep right and watch for one-way traffic.
- Slippery When Wet sign
- A yellow warning that the road becomes slick in rain or snow. Slow down and increase following distance.
- Deer / cattle crossing sign
- Animals may be on the road ahead. Scan the roadsides, slow down, and be ready to stop, especially at dusk.
- Pedestrian crossing sign
- Watch for people crossing ahead. Slow down and be ready to yield at the crosswalk.
- Bicycle crossing / share-the-road sign
- Cyclists may be on or crossing the road ahead. Slow down and give them room.
- Lane-use control arrow (overhead)
- A green arrow means the lane is open; a red X means it is closed — move out of it safely.
- HOV / carpool diamond marking
- A white diamond on the pavement marks a high-occupancy-vehicle lane reserved for cars with multiple riders.
- Curve / turn warning sign
- A yellow sign showing a bend ahead, often with an advisory speed — slow before you enter the curve.
- Reduced-speed-ahead sign
- A lower speed limit begins soon. Begin slowing now so you are at the new limit when you reach the sign.
- Regulatory vs. warning sign
- Regulatory signs (white/red) tell you a law you must obey; warning signs (yellow/orange) alert you to a hazard ahead.
- School-zone speed sign
- Reduce to the posted school-zone limit when lights flash or children are present; fines are often higher here.
- Railroad pavement marking (RXR)
- A large white 'RXR' and stop line painted on the road warn that train tracks cross ahead — be ready to stop.
- Yellow vs. white pavement lines
- Yellow lines separate traffic moving in opposite directions; white lines separate traffic moving the same way.
- Edge line (solid white at road's edge)
- Marks the outer edge of the travel lane; stay inside it except when legally pulling off the road.
- Arrow-only turn lane
- A white arrow painted in a lane means that lane must be used for the movement shown (left, right, or straight).
- Faded but yellow diamond sign
- Even if the words are unreadable, the shape and color tell you it is a general warning — slow and stay alert.
- Steady vs. flashing red
- Steady red: stop and wait for green. Flashing red: stop, yield, then go when safe — like a STOP sign.
- Steady vs. flashing yellow
- Steady yellow: prepare to stop, the light is changing. Flashing yellow: slow down and proceed with caution.
- No-passing pennant location
- The pennant-shaped 'No Passing Zone' sign is posted on the LEFT side of the road, facing the driver.
- Right-of-way (the core rule)
- Right-of-way is given, never taken. When unsure who goes first, yield. Lawful right-of-way protects you only if you use it safely.
- Four-way stop, who goes first
- The first vehicle to come to a complete stop goes first. If two stop at the same time, the one on the left yields to the one on the right.
- Turning left at an intersection
- A driver turning left must yield to oncoming traffic going straight and to pedestrians before completing the turn.
- Entering from a driveway or alley
- When pulling onto a road from a driveway, alley, or parking lot, yield to all traffic and pedestrians already on the road.
- Uncontrolled intersection
- With no signs or signals, slow down and yield to any vehicle that arrived first or is on your right.
- T-intersection right-of-way
- Traffic on the road that ends (the stem of the T) yields to traffic on the through road.
- Pedestrian in a crosswalk
- Always yield and stop for pedestrians in or entering a crosswalk; never pass a vehicle stopped for a pedestrian.
- Emergency vehicle approaching
- When a police car, fire truck, or ambulance uses lights and siren, pull to the right edge of the road and stop until it passes.
- Roundabout right-of-way
- Yield to traffic already circulating, enter to the right when there is a gap, keep moving counter-clockwise, and signal before exiting.
- Right turn on red
- In most states you may turn right on a steady red after a full stop, unless a sign prohibits it, yielding to pedestrians and cross traffic.
- Left turn on red (one-way to one-way)
- Many states allow a left turn on red from a one-way street onto another one-way street after a complete stop, unless a sign forbids it.
- Speed limit principle
- Posted limits are the maximum for ideal conditions. You must slow below them for rain, fog, traffic, curves, or poor visibility.
- Basic speed law
- You must always drive at a speed that is reasonable and safe for current conditions — even when that is below the posted limit.
- School-zone speed
- Slow to the posted school-zone limit (often 15–25 mph) when children are present or the warning lights are flashing.
- Residential / business district speed
- Unposted limits are typically around 25 mph in cities, towns, and residential areas — exact figures vary by state.
- Highway speed limits
- Open-highway and freeway limits are higher (often 55–75 mph, set by each state). Always obey the posted number.
- Minimum speed
- Driving far below the flow of traffic can be unsafe and illegal on highways; keep up with traffic when conditions allow.
- Signaling turns
- Signal at least 100 feet (about 5 seconds on the highway) before turning or changing lanes so others can react.
- Turning from the correct lane
- Turn from the lane closest to the direction you are going: right turns from the right lane, left turns from the left lane.
- Passing rules
- Pass only where markings allow, when oncoming lanes are clear, and return only after you can see the passed vehicle in your mirror.
- No-passing situations
- Never pass on a hill or curve, near an intersection or railroad crossing, or where a solid line is on your side.
- Lane positioning
- Keep right except to pass. Slower traffic should stay in the right lane; left lanes are for passing.
- Stopping at a stop sign
- Make a full stop behind the stop line or crosswalk, look left-right-left, and proceed only when it is clear.
- Yielding to oncoming traffic
- A driver turning across traffic (a left turn) must wait for a safe gap and yield to vehicles coming straight through.
- U-turn rules
- Make U-turns only where they are legal and safe, never on a curve or hill where you cannot be seen, and yield to all traffic.
- Parking distance from a fire hydrant
- Do not park within about 15 feet of a fire hydrant (the exact distance varies by state) so it stays accessible.
- Parking on a hill (facing downhill)
- Turn your front wheels toward the curb and set the parking brake so the car rolls into the curb, not into traffic.
- Parking on a hill (facing uphill)
- Turn your front wheels away from the curb (with a curb) so the rear tire catches the curb if the car rolls back.
- No-parking zones
- Never park in a crosswalk, on a sidewalk, in front of a driveway, in a bike lane, or where a sign prohibits it.
- Graduated Driver Licensing (GDL)
- A staged system that eases new (usually teen) drivers in — learner's permit, then a restricted/provisional license, then full privileges.
- Learner's permit
- The first GDL stage. The holder may drive only with a licensed adult in the front seat and after passing the knowledge test.
- Provisional / intermediate license
- The middle GDL stage, often with night-driving and passenger limits for new drivers until they gain experience.
- Why GDL exists
- New drivers crash most in their first months; phasing in privileges gives low-risk practice and reduces teen crashes.
- Implied consent
- By driving, you agree to take a chemical test for alcohol or drugs if lawfully arrested for impaired driving; refusing brings a license suspension.
- Point systems
- Most states add demerit points to your record for violations; accumulating too many in a set period can suspend your license.
- Pedestrian right-of-way at signals
- Even with a green light, you must yield to pedestrians already in the crosswalk before turning.
- Funeral procession
- Yield to a funeral procession and do not cut into or through it; the lead vehicle usually shows its hazard or flashing lights.
- Blind / disabled pedestrian
- Always yield to a pedestrian using a white cane or guide dog; they have the right-of-way and may not see you.
- Open-intersection rule
- At an intersection with no controls, the vehicle on the left yields to the vehicle on the right when both arrive together.
- Merging onto a freeway
- Use the on-ramp to match the speed of freeway traffic, then merge into a gap; entering traffic yields to traffic already on the freeway.
- Yielding when changing lanes
- A driver changing lanes must yield to vehicles already in the target lane and signal before moving over.
- Backing up safely
- Check behind the vehicle before and while backing, turn to look over your shoulder, and back slowly; yield to all traffic and pedestrians.
- Right-of-way is never 'taken'
- Insisting on the right-of-way when another driver does not yield can cause a crash; give it up to stay safe.
- Stopping for a stopped school bus
- When a bus shows flashing red lights and an extended stop arm, you must stop in both directions, except where a physical median divides the road.
- Crosswalk stopping distance
- Stop before the crosswalk or stop line, not on it, so pedestrians have a clear, safe path across.
- Three-second following rule
- Stay at least three seconds behind the vehicle ahead. Pick a fixed point it passes, then count 'one-thousand-one, -two, -three.'
- Increasing following distance
- Add a second or more in rain, fog, snow, heavy traffic, at night, or when following a motorcycle or large truck.
- Space cushion
- Keep open space on all sides of your vehicle so you have room to brake, steer, or escape a hazard.
- Blind spots
- Areas beside and behind your car that mirrors do not show. Turn your head to check them before changing lanes.
- Scanning ahead
- Look 10–15 seconds (a block or more) down the road, not just at the car ahead, so you spot hazards early.
- Checking mirrors
- Glance at your mirrors every few seconds and before braking, turning, or changing lanes to stay aware of traffic around you.
- Legal BAC limit (most states)
- It is illegal to drive with a blood alcohol concentration (BAC) of 0.08% or higher (0.04% for commercial drivers).
- DUI / DWI
- Driving Under the Influence (or While Intoxicated) — operating a vehicle impaired by alcohol or drugs; a serious, often jailable offense.
- Zero tolerance for under-21 drivers
- Drivers under 21 may have essentially no alcohol in their system; even a very low BAC is a violation in every state.
- Alcohol and reaction time
- Alcohol slows reaction time, blurs vision, and impairs judgment. Only time makes you sober — coffee and cold air do not.
- Drugs and driving
- Illegal drugs, marijuana, and even some prescription or over-the-counter medicines can impair driving and lead to a DUI.
- Drowsy driving
- Fatigue impairs you much like alcohol. If you feel sleepy, pull over to rest — open windows and radio do not keep you awake.
- Distracted driving
- Anything that takes your eyes, hands, or mind off driving — texting, phones, eating, or grooming — sharply raises crash risk.
- Texting and handheld phones
- Most states ban texting while driving, and many ban holding a phone; use hands-free mode and keep your attention on the road.
- Seat belts
- Buckle up every trip; seat belts greatly reduce injury and death and are required by law in nearly every state.
- Child safety seats
- Children must ride in an age- and size-appropriate car seat or booster; younger children belong in the back seat.
- Air bags
- Air bags work with seat belts, not instead of them. Keep a safe distance from the steering wheel and never disable them.
- Stopping distance
- Total stopping distance = perception + reaction + braking distance, and it grows sharply as speed increases.
- Speed and crash severity
- Higher speed means longer stopping distance and far greater crash force, so excessive speed is a leading cause of fatal crashes.
- Hydroplaning
- At higher speeds on wet roads, tires can ride up on a film of water and lose grip. Slow down and avoid standing water.
- Recovering from a skid
- Ease off the gas, do not slam the brakes, and steer gently in the direction you want the front of the car to go.
- Driving in rain
- Slow down, turn on low-beam headlights, increase following distance, and use wipers; the first rain after a dry spell is most slippery.
- Driving in fog
- Slow down, use low beams (high beams reflect back and reduce vision), and if it is too thick, pull completely off the road.
- Driving in snow and ice
- Slow way down, brake and steer gently, increase following distance, and watch for black ice on bridges and shaded spots.
- Night driving
- Reduce speed, use high beams on open road, and dim to low beams for oncoming traffic and when following closely.
- Dimming high beams
- Switch to low beams within about 500 feet of an oncoming vehicle and about 200–300 feet behind one you are following.
- Overdriving your headlights
- Driving so fast you cannot stop within the distance your headlights light up is dangerous; slow to a safe speed at night.
- When to use headlights
- Turn on headlights from dusk to dawn and any time weather (rain, fog, snow) reduces visibility; many states require them with wipers.
- Hazard (emergency) flashers
- Use them when stopped or disabled on or beside the road to warn others; most states bar using them while driving normally.
- Braking on a long downgrade
- Shift to a lower gear to use engine braking and avoid overheating (fading) the brakes from constant pressure.
- Tire condition and tread
- Worn or underinflated tires reduce grip and raise the risk of skids and blowouts; check tread and pressure regularly.
- Brake failure
- Pump the brakes, downshift, and use the parking brake gradually; steer to a safe spot and warn others with horn and flashers.
- Tire blowout
- Grip the wheel firmly, ease off the gas, let the car slow, and steer straight; do not brake hard until you have control.
- Defensive driving
- Anticipating hazards and others' mistakes, keeping a space cushion, and always having an escape path to avoid crashes.
- Aggressive driving / road rage
- Tailgating, weaving, and speeding endanger everyone. Stay calm, give angry drivers room, and do not engage or retaliate.
- Adjusting mirrors and seat
- Set your seat and mirrors before driving so you can reach the controls, see clearly, and minimize blind spots.
- Two-second rule vs. three-second rule
- A minimum following gap of two seconds in ideal conditions; three or more seconds is safer and standard for most situations.
- Driving when emotional or stressed
- Strong emotions impair judgment like fatigue or alcohol. Calm down before driving and avoid taking feelings out on the road.
- Headlight use in tunnels and shade
- Turn on low beams entering tunnels or heavy shade so you can see and be seen as light changes quickly.
- Cruise control in bad weather
- Do not use cruise control on wet, icy, or snowy roads — it can keep power on during a skid and worsen loss of control.
- Glare from sun or headlights
- Use your visor, slow down, and look toward the right edge of your lane to keep your bearings until the glare passes.
- Highway hypnosis
- Long, monotonous driving can dull alertness. Keep your eyes moving, take breaks, and stay engaged with the road.
- Driving through deep water
- Avoid flooded roads — 'Turn Around, Don't Drown.' Even shallow moving water can stall the engine or sweep a car away.
- Anti-lock brakes (ABS)
- With ABS, press and hold firm, steady pressure in an emergency stop and steer; do not pump the brakes.
- Following large trucks
- Stay back so you can see and be seen; trucks have big blind spots ('No-Zones') and need much longer to stop.
- Field sobriety and chemical tests
- Officers may test impairment with field tasks or a breath/blood test; impaired driving brings fines, license loss, and jail.
- Don't drink and drive — the only safe choice
- There is no safe number of drinks. Plan a sober driver, rideshare, or stay put — the test rewards the most cautious choice.
- Stopping for a stopped school bus
- When a school bus shows flashing red lights and an extended stop arm, stop in both directions and wait until it withdraws — except where a physical median divides the road.
- School bus flashing amber (yellow) lights
- The bus is about to stop. Slow down and prepare to stop; do not try to pass it before the red lights come on.
- Painted line vs. physical median (school bus)
- A painted center line or turn lane is NOT a median; you must still stop. Only a raised barrier or grassy median exempts oncoming traffic.
- Sharing the road with motorcycles
- Give motorcycles a full lane and extra following distance; they are small, easy to miss, and can stop quickly.
- Checking blind spots for motorcycles
- Always look twice and check mirrors and blind spots before changing lanes or turning — motorcycles hide easily.
- Motorcyclist lane position
- Riders shift within a lane to be seen and avoid hazards; do not crowd them or treat the extra space as room to share the lane.
- Sharing the road with bicycles
- Treat cyclists as vehicles, pass with at least 3 feet of space (where required), and check for them before turning right.
- Right turn across a bike lane
- Before turning right, yield to and merge carefully around bicyclists in the bike lane; do not cut them off.
- Large trucks' blind spots (No-Zones)
- Trucks have large blind spots front, rear, and sides. If you cannot see the driver's mirror, they cannot see you.
- Trucks turning right
- A large truck may swing left before turning right; never try to pass it on the right while it is turning.
- Passing a large truck
- Pass promptly on the left, avoid lingering beside it, and return only when you can see its full front in your mirror.
- Emergency vehicles with lights and siren
- Pull to the right edge of the road and stop until it passes; if you are in an intersection, clear it first, then pull over.
- Move Over law
- Move one lane away from a stopped emergency, police, tow, or service vehicle showing flashing lights; if you cannot, slow down and pass with caution.
- Work zones
- Slow down, obey reduced limits and flaggers, expect sudden stops and lane shifts, and watch for workers; fines are often doubled.
- Flagger in a work zone
- A flagger's signals override signs and signals. Follow their directions to stop, slow, or proceed through the zone.
- Railroad crossings
- Slow down, look and listen, and never stop on the tracks. If gates lower or lights flash, stop and wait for the train to pass.
- Stalling on railroad tracks
- Get everyone out and away from the tracks immediately, then call the posted emergency number or 911 — never try to move the car.
- Pedestrians and crosswalks
- Yield to pedestrians in or entering any crosswalk, marked or unmarked, and never pass a car stopped for a pedestrian.
- Children and school zones
- Slow down, expect sudden movements, and stop for crossing guards; children may dart into the street without looking.
- Slow-moving and farm vehicles
- Tractors and other slow vehicles displaying the orange triangle travel under 25 mph; slow down and pass only when safe and legal.
- Animals on or near the road
- Slow down, do not swerve hard (you could lose control or hit something worse), brake straight, and watch for more animals.
- Driving near pedestrians at night
- Pedestrians are hard to see after dark; reduce speed and scan crosswalks and roadsides, especially in towns and near bars.
- Roundabouts and large vehicles
- Give trucks and buses extra room in a roundabout; they may need both lanes, so do not drive beside them through the circle.
- Sharing the road with buses
- Yield to a transit bus signaling to re-enter traffic where required by law, and never pass a bus stopped to load passengers unsafely.
- Funeral processions
- Do not cut into or break up a funeral procession; the vehicles usually follow a lead car with flashers and stay together.
- Vulnerable road users
- Pedestrians, cyclists, motorcyclists, and roadside workers have little protection; give them extra space, time, and attention.
- Construction speed limits
- Reduced work-zone limits apply whether or not workers are present; slow to the posted number to avoid a costly ticket and a crash.
- Stopping for emergencies in an intersection
- If an emergency vehicle approaches while you are in an intersection, continue through and clear it before pulling to the right.
- Driving in a flood or severe storm
- Avoid driving in severe weather; if water covers the road, turn around. Pull off safely if visibility or control is lost.
- Mountain and steep-grade driving
- Use lower gears downhill, watch for runaway-truck ramps and slow vehicles, and yield to uphill traffic on narrow roads.
- Highway entrance and exit ramps
- Use the entrance ramp to reach traffic speed, and slow only after you have left the freeway on the exit ramp.
- Stopping on the shoulder
- Pull completely off the road, turn on hazard flashers, and stay aware of passing traffic; exit the car on the side away from traffic.
- Disabled vehicle on the highway
- Get the vehicle off the travel lanes if possible, use flashers and warning devices, and stand well away from traffic.
- Passing on a two-lane road
- Pass only with a clear view ahead, a broken line on your side, and enough room to return safely before oncoming traffic arrives.
- Yielding to transit and school traffic
- Give buses room to merge and stop, watch for loading passengers, and never pass on the side where people board or exit.
- Wildlife crossing zones
- Where deer or other animals are common, slow down at dawn and dusk, use high beams when alone, and scan the road edges.
- Sharing the road with pedestrians using mobility aids
- Give people in wheelchairs or using walkers or canes extra time and space; they have the right-of-way in crosswalks.
- Following an emergency vehicle
- Stay at least 500 feet behind a responding emergency vehicle (where required); do not tailgate or follow to 'beat' traffic.
- Approaching a crash or stopped traffic
- Slow early, watch for pedestrians and responders, move over for stopped vehicles, and follow any directions from officers.
- Trucks and uphill / downhill speed
- Heavy trucks lose speed climbing hills and gain it descending; give them room and do not box them in on grades.
- Bicyclists at intersections
- Cyclists may proceed straight from a bike lane while you turn right; yield and check before crossing their path.
- Driving past parked cars
- Watch for opening doors, pedestrians stepping out, and cars pulling from the curb; leave room and cover the brake.
- School crossing guards
- Stop and wait when a crossing guard signals; their direction controls the intersection while children cross.
- Light-rail and streetcars
- Yield to trains and streetcars, never turn across their path against a signal, and watch for riders crossing to and from stops.
- Reacting to an aggressive driver
- Do not engage. Let them pass, keep your distance, avoid eye contact, and report dangerous driving when you can safely.
- Sharing roads with horse-drawn vehicles
- Slow down, do not honk or rev your engine, and pass wide and slowly so you do not startle the animal.
- Driving near emergency scenes
- Obey responders' directions, slow to the posted or safe speed, and move over to protect people working at the scene.
- Why right-of-way rules vary by state
- Core rules (signs, signals, DUI ~0.08%, right-of-way, GDL) are shared nationwide, but specific limits, ages, and penalties are set by each state — always check your state's driver manual.