ROAD SIGN HERO
Today's 5 signs

Rules of the road

The US traffic rules behind our games, in plain English. Each one says where it comes from and whether it changes from state to state.

The United States has no single traffic code. Every state writes its own, but most follow the same model law, the Uniform Vehicle Code, and every state uses the same signs, lights and lane lines from the federal MUTCD. That is why most of the rules below are the same wherever you drive. Where a number or an exception changes from state to state — how far from a fire hydrant you may park, whether you may turn left on red — the rule is marked Differs by state, and our games explain it without taking points for it. Your own state's driver handbook is always the official source.

Practice them: Right of Way for intersections, Signal Lab for lights, lines and special vehicles, and the Road Rules roads in Road Sign Adventure to drive them in 3D.

Right-of-way

Same in nearly every stateStopped at the same time: yield to the right

If two vehicles stop at the same time, the driver on the left yields to the driver on the right.

What to do: Look right. If a car on your right stopped when you did, it goes first.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Right-of-way rules — intersections; Florida Statutes §316.123 (stop signs, four-way stops), (2)(b) same time: the vehicle on the left yields to the vehicle on the right

Same in nearly every stateStop sign, cross traffic doesn't stop

At a stop sign where cross traffic has no stop sign, stop, then yield to every vehicle on the cross street that is close enough to be a danger.

What to do: Stop at the line, look left, right and left again, and go only when the cross street is clear.

Source: Florida Statutes §316.123 (stop signs, four-way stops), (2)(a) after stopping, yield to vehicles in or close to the intersection; Uniform Vehicle Code (NCUTLO) — the model most state codes follow, §11-403 stop and yield signs

Same in nearly every stateNo signs or lights: first there, then the car on the right

At an intersection with no signs or signals, the vehicle that gets there first goes first; if two arrive together, yield to the vehicle on the right.

What to do: Slow down as you approach and be ready to stop for anyone already there or on your right.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Right-of-way rules — intersections without STOP or YIELD signs; Uniform Vehicle Code (NCUTLO) — the model most state codes follow, §11-401 vehicles approaching an intersection

Same in nearly every stateT-intersection: the through road goes first

At a T-intersection with no signs, vehicles on the through road have the right-of-way over the road that ends.

What to do: If your road ends at the T, yield to traffic on the road you are joining.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Right-of-way rules — T intersections

Same in nearly every stateGreen light: the intersection must be clear

A green light lets you go only after vehicles and people still in the intersection are out of your way, and only if you can get all the way across.

What to do: On green, look left and right first. Don't enter if traffic would leave you stuck in the intersection.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Traffic signal lights — solid green

Same in nearly every stateRoundabouts: yield to cars already in the circle

Entering a roundabout, yield to all traffic already in it. Drive counterclockwise and don't stop inside.

What to do: Slow down, look left, and enter to the right when there is a gap big enough to merge.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Roundabouts

Same in nearly every stateLeaving a driveway or parking lot

A driver coming out of a driveway, alley or parking lot yields to all traffic on the road and to people on the sidewalk.

What to do: Stop before the sidewalk, then pull out only into a clear gap.

Source: Uniform Vehicle Code (NCUTLO) — the model most state codes follow, §11-404 vehicle entering highway from private road or driveway (not yet checked against the handbook text)

Same in nearly every statePeople in the crosswalk go first

Yield to pedestrians in any crosswalk — marked with lines or unmarked at an intersection.

What to do: Stop before the crosswalk and wait until the person is out of your path.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Pedestrians

Same in nearly every stateWhite cane or guide dog: always yield

A person using a white cane or a guide dog always has the right-of-way.

What to do: Stop and wait. Don't honk or wave — the person may be listening for traffic.

Source: California Driver's Handbook (California DMV, online edition), Section 8: Sharing the road — blind pedestrians

Traffic lights

Same in nearly every stateSteady yellow: stop if you safely can

A steady yellow light means red is coming. Stop if you can do so safely; if you are too close to stop, go through carefully.

What to do: Brake if you can stop before the line without slamming the brakes.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Traffic signal lights — solid yellow

Same in nearly every stateFlashing red = stop sign

A flashing red light means STOP. After stopping, go when it is safe, following stop-sign rules.

What to do: Treat it exactly like a stop sign.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Traffic signal lights — flashing red

Same in nearly every stateFlashing yellow = go with caution

A flashing yellow light is a warning: you don't have to stop, but slow down and be alert.

What to do: Ease off, look both ways, keep going if it is clear.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Traffic signal lights — flashing yellow

Same in nearly every stateGreen arrow: protected turn

A green arrow means you may turn that way; oncoming traffic has a red light.

What to do: Turn — but still yield to anyone still in the intersection.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Traffic signal lights — green arrow

Same in nearly every stateRight turn on red

You may turn right on a red light after a full stop, yielding to pedestrians and traffic — unless a NO TURN ON RED sign is posted.

What to do: Stop at the line first, look left for traffic and right for people, then turn.

New York City bans right on red unless a sign allows it. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Right turn on red

Differs by stateLeft 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 going left, after a full stop and yielding.

What to do: Only do it if your state allows it, both streets are one-way, and no sign forbids it.

Some states do not allow it at all. Check your state's driver handbook.

Source: Uniform Vehicle Code (NCUTLO) — the model most state codes follow, §11-202 traffic-control signal legend (not yet checked against the handbook text)

Lines on the road

Same in nearly every stateYellow lines vs white lines

Yellow lines separate traffic going in opposite directions. White lines separate lanes going the same way.

What to do: Keep yellow on your left. If yellow is on your right, you're on the wrong side.

Source: Manual on Uniform Traffic Control Devices, 11th edition (FHWA, 2023), Part 3, longitudinal pavement markings (not yet checked against the handbook text)

Same in nearly every stateWhen the lines let you pass

You may pass when a broken yellow line is on your side and it is safe. Don't cross a solid yellow line on your side or double solid yellow lines to pass.

What to do: Pass only on a broken line, only when you can see far enough ahead.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Lane markings

Same in nearly every stateCenter left-turn lane

The shared center lane (yellow solid and broken lines on each side) is only for starting or finishing a left turn — never for driving along or passing.

What to do: Move into it just before your turn, then turn when oncoming traffic is clear.

California allows at most 200 feet of driving in it; the limit differs by state. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Center left turn lanes

Speed

Same in nearly every stateBasic speed law

Never drive faster than is safe for the conditions — rain, fog, traffic, curves — even below the posted limit.

What to do: In bad weather or heavy traffic, slow down below the sign.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Speed limits — basic speed law (not yet checked against the handbook text)

Differs by stateSchool zone speed

Near schools, a lower limit applies while children are present or the beacons flash.

What to do: Slow down to the school limit and watch for children.

California: 25 mph within 500 feet of a school while children are outside or crossing. Other states post 15–25 mph. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Speed limits — around children

Differs by stateLimits that aren't posted

Some places have a legal limit even without a sign — alleys, blind intersections and railroad crossings you can't see down.

What to do: Slow way down where you can't see what is coming.

California: 15 mph in alleys, at blind intersections and within 100 feet of a railroad crossing you can't see 400 feet down. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Speed limits

Following distance

Same in nearly every stateThree-second rule

Stay at least three seconds behind the vehicle ahead, and more in rain, at night, or behind trucks and motorcycles.

What to do: When the car ahead passes a sign, count: you should reach it no sooner than three seconds later.

Source: California Driver's Handbook (California DMV, online edition), Section 8: Following distances — three-second rule

Lanes, turns and passing

Same in nearly every stateSignal before you turn or change lanes

Use your turn signal before every turn and lane change, early enough for others to react.

What to do: Signal, check mirrors, look over your shoulder, then move.

California: about 100 feet before a turn. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Turn signals

Same in nearly every stateTurn into the nearest lane

Right turns start and end in the right lane; left turns start in the left-most lane and end in the nearest lane going your way.

What to do: Don't swing wide. Change lanes after the turn, not during it.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Right turns and left turns

Same in nearly every stateKeep right, pass on the left

Drive in the right lane except to pass; pass other vehicles on the left.

What to do: After passing, move back right once you can see the passed car in your mirror.

Source: Uniform Vehicle Code (NCUTLO) — the model most state codes follow, §11-301, §11-303 driving on the right; passing on the left (not yet checked against the handbook text)

Same in nearly every stateWhere never to pass

Don't pass on curves or hills where you can't see ahead, within an intersection, or near a railroad crossing.

What to do: Wait for a straight road with a broken line and a clear view.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Passing (not yet checked against the handbook text)

Differs by stateWhere U-turns are not allowed

No U-turn where a sign forbids it, where you can't see far enough, on a one-way street, at a railroad crossing, or across a divided highway's median.

What to do: When in doubt, go around the block.

California also bans U-turns in business districts except at intersections, and in front of fire stations. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 6: U-turns

Same in nearly every stateMerging onto a highway

Traffic already on the highway has the right-of-way. Use the on-ramp to reach the speed of traffic and merge into a gap.

What to do: Speed up on the ramp, signal, find your gap, and never stop at the end of the ramp unless you must.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Merging in and out of traffic (not yet checked against the handbook text)

Emergency vehicles, buses, trains, bikes

Same in nearly every stateMove Over law

When a police car, ambulance, fire truck or tow truck is stopped on the shoulder with its lights flashing, move over a lane — or slow down if you can't.

What to do: Change to the lane away from the shoulder when it is clear; otherwise slow well down.

Every state has a Move Over law, but which vehicles it covers and how much to slow down differ. Check your state's driver handbook.

Source: NHTSA Traffic Safety Marketing: Move Over, Move Over: it's the law in every state; California Driver's Handbook (California DMV, online edition), Section 7: Move over and slow down

Same in nearly every stateSchool bus with flashing red lights

When a school bus flashes red lights and puts out its stop arm, stop — whether you are behind it or coming toward it — until the lights stop flashing.

What to do: Stop well back and wait. Children may cross in front of the bus.

On a divided highway, traffic on the other side usually doesn't stop; the exact rule differs. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Around children — school buses

Same in nearly every stateRailroad crossings

When lights flash, gates come down or a train is near, stop 15 to 50 feet from the nearest rail. Never stop on the tracks.

What to do: Wait for every train — there may be a second track — and cross only when there is room on the other side.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Near railroad or light rail tracks; Uniform Vehicle Code (NCUTLO) — the model most state codes follow, §11-701 obedience to signal indicating approach of train

Differs by statePassing a bicycle

Give a bicyclist plenty of room when you pass — at least 3 feet in many states.

What to do: Slow down and wait until you can pass with room to spare.

California and many other states set 3 feet by law; a few ask for more or change lanes. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 8: Sharing the road — bicycles

Same in nearly every stateTrucks: no-zones and wide turns

Large trucks have big blind spots on every side and swing wide to turn right.

What to do: Don't linger beside a truck, and never squeeze in on its right when it signals a right turn.

Source: California Driver's Handbook (California DMV, online edition), Section 8: Large trucks (not yet checked against the handbook text)

Parking

Same in nearly every stateParking on a hill

Uphill with a curb: wheels turned away from the curb. Downhill: wheels turned toward the curb. No curb: wheels turned toward the edge of the road. Always set the parking brake.

What to do: Turn the wheels so the car would roll into the curb or off the road, not into traffic.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Parking on a hill

Differs by stateParallel parking distance

Park parallel to the curb and close to it.

What to do: Finish with your wheels straight and close to the curb.

California: within 18 inches of the curb. Other states use 12 or 18 inches. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Parallel parking

Differs by statePlaces you can't park

Never park in an intersection, on a crosswalk or sidewalk, blocking a driveway, or next to a fire hydrant.

What to do: Leave space around hydrants, crosswalks and corners.

California: 15 feet from a fire hydrant and 20 feet from a crosswalk; distances differ elsewhere. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 6: Illegal parking

Night and bad weather

Same in nearly every stateHeadlights on at night and in bad weather

Turn your headlights on from sunset to sunrise and whenever it is hard to see — rain, fog, snow.

What to do: If you need your wipers, you need your headlights.

California: from 30 minutes after sunset to 30 minutes before sunrise, and when you can't see 1,000 feet ahead. Many states also require them whenever your wipers are on. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 5: Use your headlights

Differs by stateDim your high beams

Switch to low beams when a car is coming toward you or when you are following close behind one.

What to do: Dim for oncoming cars and when you follow someone.

California: dim within 500 feet of an oncoming car and 300 feet of a car you are following. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 8: Use your headlights

Same in nearly every stateHydroplaning

On a wet road your tires can ride up on water and lose grip. Slow down gradually — don't slam the brakes or turn sharply.

What to do: Ease off the gas and keep the wheel straight until the tires grip again.

Source: California Driver's Handbook (California DMV, online edition), Section 8: Hydroplaning

Phones, alcohol, seat belts, crashes

Same in nearly every stateNo texting while driving

Texting while driving is banned in 49 states and Washington, D.C.

What to do: Put the phone away before you start the car.

33 states and D.C. also ban holding the phone at all, and most ban all phone use by new drivers. Check your state's driver handbook.

Source: GHSA: Distracted driving laws by state, State laws table (updated June 2025)

Same in nearly every stateUnder 21: zero tolerance

Every state sets a blood-alcohol limit of 0.02% or lower for drivers under 21 — in practice, any drinking.

What to do: Under 21: don't drink at all if you are driving.

Source: CHOP Teen Driver Source: Impaired driving laws, Zero tolerance laws

Same in nearly every stateSeat belts

The driver and passengers must wear seat belts, and children must ride in the right car seat.

What to do: Everyone buckles up before the car moves.

New Hampshire has no seat belt law for adults; every other state does. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 7: Seat belts (not yet checked against the handbook text)

Same in nearly every stateAfter a crash

Stop, help anyone hurt and call 911, and exchange names, license and insurance details. Leaving the scene is a crime.

What to do: Stop safely, check on people, call for help, swap information.

California: report to the DMV within 10 days if anyone was hurt or damage is over $1,000. Other states differ. Check your state's driver handbook.

Source: California Driver's Handbook (California DMV, online edition), Section 10: Collisions — what to do after a collision