Traffic signsUnited States

Yes, where local traffic rules permit. Horses may be ridden, led or used with animal-drawn vehicles on public roads and designated routes.

Drivers should slow down, leave plenty of space and pass calmly, avoiding unnecessary horn use, sudden acceleration or other actions that could frighten the horse.

Yes. Horse riders using a road are road users and must follow the traffic rules that apply to riders and animals in that country.

Local traffic generally means vehicles that have a legitimate reason to enter a particular street or area, such as reaching a home, business, delivery address or other destination located there.

No. Through traffic passes through an area without having a destination or other necessary stop there. A restriction allowing only local traffic is normally intended to prevent this type of unnecessary through traffic.

This depends on national rules and the signs in place. Residents, visitors, deliveries, emergency services and certain service vehicles are commonly permitted, but the precise categories vary between countries.

A pedestrian is primarily a person travelling on foot. Local traffic laws may also treat people pushing bicycles, wheelchairs, prams or certain other devices as pedestrians.

Pedestrians should normally use pavements, sidewalks, footpaths or other areas provided for pedestrians. Where these are unavailable, local rules determine where pedestrians may walk on or beside the road.

This depends on the country's traffic rules. Many countries require or recommend pedestrians to face approaching traffic, but the exact rule varies.

Use a pedestrian crossing, traffic-light-controlled crossing or other designated crossing where required or reasonably available. Where crossing elsewhere is permitted, choose a location with good visibility and cross carefully.

The exact priority rule varies between countries. Drivers are commonly required to give way to pedestrians using or entering designated crossings, but pedestrians must still obey traffic lights and avoid entering the road dangerously.

Yes. Where pedestrian signals are provided, pedestrians must follow their indications and should not enter the roadway while the signal prohibits crossing.

In many traffic systems, a person who dismounts and walks beside a bicycle is treated as a pedestrian. The precise legal classification depends on local law.

This depends on the road layout and local rules. Pedestrians may sometimes use a cycle path when no suitable pedestrian facility is available, but they must not unnecessarily obstruct cyclists or other authorised users.

Yes. Drivers turning into another road must watch carefully for pedestrians crossing the road they are entering and give way where required by local traffic law.

Check carefully for approaching traffic from all relevant directions, make sure there is sufficient time and distance to cross safely, and continue to observe traffic while crossing.

A cyclist is a person who rides and controls a bicycle.

Yes. Cyclists are road users and must follow the traffic rules, signs and signals that apply to them.

This depends on local rules. Cyclists may be required to use a cycle path or designated cycling facility, while in other situations they may ride on the carriageway.

A motorcycle is a powered two-wheeled vehicle, which may also be equipped with a sidecar.

No. Traffic laws generally distinguish motorcycles from mopeds according to technical characteristics such as power, engine capacity or maximum speed.

Motorcyclists should use an approved helmet and suitable protective clothing. The exact mandatory equipment depends on the country's traffic laws.

A truck is a motor vehicle designed primarily for transporting goods.

No. Trucks can include lighter goods vehicles as well as heavy trucks. Traffic laws often apply different rules according to the vehicle's maximum authorised mass.

Trucks may have larger blind spots, longer stopping distances and wider turning paths than smaller vehicles, so other road users should avoid remaining unnecessarily close beside or in front of them.

A bus is a motor vehicle designed to transport a relatively large number of passengers. It may be used for public transport, school transport, private services or other passenger transport.

A bus is commonly designed for frequent passenger boarding and may allow standing passengers, while a coach is generally designed for longer journeys with passengers seated. Exact legal definitions vary between countries.

Yes. Driving a vehicle designed to carry more than a specified number of passengers normally requires a dedicated bus or passenger-vehicle driving licence.

Only when the vehicle is designed and approved to carry standing passengers. Coaches and other vehicles designed exclusively for seated passengers must not be used beyond their approved passenger configuration.

Where seat belts are provided and local law requires their use, passengers must wear them correctly. Urban buses designed for standing passengers may have seating positions or operating conditions that differ from coaches.

Yes, where permitted. Bus lanes are commonly reserved for public transport buses, although local signs may also allow taxis, bicycles or other specified vehicles to use them.

No. Some countries require other drivers to give way to buses leaving designated stops, particularly in urban areas, while others apply the normal merging rules.

Yes. Passengers may be boarding, leaving or crossing the road near the bus. Reduce speed where necessary and watch carefully for pedestrians emerging from behind or in front of the vehicle.

They can. Some countries impose lower maximum speeds on buses than on passenger cars, particularly on high-speed roads. Different limits may apply to buses and coaches.

Yes, normally. Buses that satisfy the applicable construction and access requirements may use motorways, but they must obey any vehicle-specific speed limits, lane restrictions and other local rules.

Police help enforce traffic laws, manage traffic, investigate collisions and respond to dangerous situations. They may also carry out roadside checks and direct road users.

Yes. Lawful directions given by an authorised police officer must be followed. In many countries, those directions take precedence over traffic lights, road signs and normal priority rules.

Slow down, follow the officer's directions and stop at a safe location as instructed. Do not make sudden movements or continue driving unless directed to do so.

Yes, where authorised by local law. A police officer controlling traffic may instruct road users to proceed even when a traffic light or sign would normally require them to stop.

Yes. Police may require drivers to provide documents such as a driving licence, vehicle registration, identification or proof of insurance according to local law.

Yes. Traffic police may conduct legally authorised alcohol and drug checks using procedures such as breath, saliva or other approved tests.

Yes. Roads or lanes may be temporarily closed or traffic diverted because of collisions, emergencies, investigations, public events or other safety concerns.

Reduce speed, remain alert and follow all directions. Do not enter a closed area or interfere with emergency personnel, and leave sufficient space for emergency vehicles.

Follow the local rules for priority vehicles. Drivers generally have to make sufficient space, give way and stop where necessary so that the emergency vehicle can pass safely.

Yes, where local law permits it. Police or another authorised authority may require a vehicle to be moved when it obstructs traffic, creates danger or must be removed for operational reasons.

An ambulance is a specially equipped vehicle used to provide emergency medical assistance and transport sick or injured people.

This depends on the local traffic rules and warning signals being used. Ambulances responding to emergencies commonly use flashing lights and a siren to indicate that other road users must make way.

Remain calm and make sufficient space for it to pass. Slow down or stop where necessary, but avoid sudden or dangerous manoeuvres.

Not necessarily in your exact position. Move or stop in a way that creates a safe passage without blocking an intersection, pedestrian crossing or another part of the road needed by the ambulance.

Emergency vehicles may be allowed to pass a red light during an urgent response under special legal conditions. The precise rules differ between countries, and the ambulance driver must still take appropriate precautions.

Many countries permit emergency vehicles to depart from certain normal speed rules during an urgent mission, subject to safety requirements and national legislation.

Yes, when responding to an emergency and legally permitted to do so. Other road users should create space and keep emergency corridors or access routes clear where required.

You should not use the passage created for an ambulance as a way to bypass congestion. Maintain a safe distance and continue to obey the normal traffic rules.

No. The use of warning lights and sirens depends on the urgency of the mission and local regulations. An ambulance transporting a patient does not necessarily need to use emergency signals throughout the journey.

Reduce speed and remain alert. Medical personnel, patients or other emergency workers may be entering the road, and the ambulance may need to move unexpectedly.

Police traffic signals are gestures, positions or other signals used by authorised officers to regulate or direct traffic.

In many countries, yes. Directions given by an authorised traffic officer normally take precedence over traffic lights, signs and ordinary traffic rules.

Slow down, pay close attention and follow the officer's instruction. Do not continue simply because a traffic light or road sign would normally allow you to proceed.

A gravel road is an unpaved road covered with gravel, crushed stone or another loose aggregate surface.

Loose material can reduce tyre grip, increase stopping distance and cause stones or dust to be thrown into the air. Potholes and uneven surfaces may also be present.

Use a suitable speed, maintain extra distance from other vehicles and accelerate, brake and steer smoothly to reduce the risk of losing traction.

A pothole is a hole or depression that develops in a road surface when the pavement becomes damaged or deteriorates.

Potholes can develop through a combination of water, temperature changes, traffic loads and deterioration of the road material. Cracks can gradually expand until pieces of the surface break away.

A pothole can cause a vehicle to change direction suddenly, lose stability or suffer tyre, wheel or suspension damage. Deep potholes can present a particularly serious hazard at higher speeds.

Reduce speed when necessary, maintain control of the vehicle and avoid abrupt steering or braking. Only move around the pothole when this can be done safely without endangering other road users.

If possible, reduce your speed before reaching the pothole. Sudden heavy braking or steering while passing over a damaged surface can make the vehicle less stable.

Yes. A pothole can disturb the steering or balance of a motorcycle and may cause the rider to lose control.

Yes. Bicycle wheels can be strongly affected by deep holes or sharp edges, particularly when the cyclist has little time or space to avoid the hazard.

Yes. Severe impacts can damage tyres, wheel rims, suspension components, steering parts or wheel alignment.

No. A sudden evasive movement may create a greater danger by bringing the vehicle into conflict with cyclists, pedestrians, oncoming traffic or vehicles in another lane.

Yes. Depending on the country's traffic-sign system, an uneven-road or general-danger warning sign may be used where poor road conditions create a significant hazard.

A median strip is a longitudinal area that separates two roadways, usually carrying traffic in opposite directions.

Not necessarily. A median is normally a physically distinguishable area or structure, while painted centre lines simply separate traffic using road markings.

A median may consist of grass, paving, kerbs, safety barriers, vegetation or another physical separation between roadways.

They help separate opposing traffic flows, reduce conflicts between vehicles travelling in opposite directions and provide space for barriers, signs, lighting or other road infrastructure.

Only where a legal crossing or opening is provided and the applicable traffic rules permit the movement. Drivers should never cross a physical median simply to change direction or take a shortcut.

Yes. Openings may be provided for intersections, turning movements, emergency services, maintenance or other authorised traffic.

This depends on local law, but parking on a median is commonly prohibited or restricted because it may create danger or obstruct visibility and traffic.

Some medians contain a pedestrian refuge specifically designed to allow people to cross a road in stages. Other medians may not be intended for pedestrian use.

It can be. A median may contain a safety barrier designed to reduce the risk of vehicles crossing into opposing traffic.

Yes. A road with a median commonly has two separate roadways, one for each direction of traffic.

The road layout normally separates the traffic directions, but drivers must still follow the traffic signs, lane markings and directional rules applying to each roadway.

No. An emergency lane or shoulder runs alongside a roadway, while a median strip separates roadways from each other.

Public property is property owned or controlled by a government, municipality or another public authority.

Examples can include roads, parks, public squares, government buildings, transport infrastructure and other public facilities.

No. Some public property is freely accessible, while access to government offices, maintenance facilities, railway infrastructure or other areas may be limited or prohibited.

No. Public property concerns ownership or control, while a public road concerns an area that is legally or actually open to public traffic. A public road can therefore be only one type of public property.

Yes. A privately owned car park, road or other area may be accessible to the public even though the government does not own it.

Yes. Public authorities can own areas that are restricted to authorised personnel, maintenance services or other specified users.

No. Whether ordinary road-traffic rules apply depends on the legal status and use of the area rather than simply on who owns it.

Yes. Public property can include streets, car parks, access roads and other traffic areas, each of which may have its own traffic and access rules.

Yes. Signs, barriers, opening hours, permits or other regulations may restrict access to particular public areas.

Yes. A publicly accessible park, square or pedestrian area may prohibit motor vehicles or permit only specific categories such as emergency, maintenance or delivery vehicles.

Not necessarily. Public space generally describes an area available for public use, while public property primarily describes ownership or control. A publicly used space can sometimes be privately owned.

Traffic regulations frequently depend on whether an area is a public road, publicly accessible place or restricted private area, rather than solely on ownership.

A path is a relatively narrow route intended primarily for pedestrians and, where permitted, other road users or small vehicles.

Not necessarily. A footpath is specifically intended for pedestrians, while a path may also permit cyclists or other users according to local rules.

No. A cycle path is specifically designated for bicycles and other permitted users. An ordinary path does not automatically have that legal status.

This depends on the legal status, width and signs applying to the path. Some paths permit cyclists, while others are reserved for pedestrians or particular users.

This depends on local law. Some paths prohibit motor vehicles entirely, while narrow vehicles may be permitted on other paths unless traffic signs restrict access.

Yes. A narrow path can legally form part of the public-road network even when it is unsuitable for ordinary cars.

No. Paths can be paved, gravelled, compacted or unsurfaced depending on their location and purpose.

Yes. Signs can reserve a path for particular road users or prohibit certain vehicles, regardless of whether they could physically fit on it.

The applicable local priority rules determine who must give way. Special rules often apply when a minor path joins an ordinary road.

Yes, where both are permitted. Faster users should adapt their speed and avoid endangering or unnecessarily obstructing pedestrians.

Yes. At the crossing, users must follow the applicable priority signs, traffic lights, road markings and general right-of-way rules.

No. Its legal classification depends on the definitions and regulations of the country concerned. A narrow route might instead be a footpath, cycle path, private access road or another type of facility.

Particulates, or particulate matter, are very small solid particles or liquid droplets suspended in the air.

PM10 refers to particles with a diameter of up to approximately 10 micrometres. PM2.5 refers to finer particles with a diameter of up to approximately 2.5 micrometres.

Road traffic can produce particles through engine exhaust, brake wear, tyre wear and road-surface wear. Passing traffic can also resuspend dust already present on the road.

Yes. Combustion in diesel engines can produce very small soot particles. Modern diesel vehicles commonly use particulate filters to capture a large proportion of these exhaust particles.

A particulate filter is an exhaust-treatment device designed to trap particulate matter produced by an engine. Diesel particulate filters are commonly known as DPFs.

Yes. Petrol engines can also produce particulate emissions, particularly certain direct-injection engines. Appropriate emission-control systems may therefore include particulate filters.

Fully electric vehicles produce no exhaust particulates from a combustion engine, but particles can still result from tyre wear, road wear and braking.

Vehicle-emission regulation is increasingly addressing non-exhaust emissions. The European Euro 7 framework includes requirements concerning brake-particle emissions and tyre abrasion.

No. Particulate matter consists of tiny airborne particles, while carbon dioxide is a gas. They are different types of vehicle emissions and are regulated for different environmental reasons.

Measures include effective particulate filters, cleaner vehicle technologies, correctly maintained emission-control systems and reductions in brake, tyre and road-wear emissions.

Air pollution is contamination of the air by gases, particles or other substances that can adversely affect human health, the environment or ecosystems.

Vehicles produce pollutants through fuel combustion, exhaust systems, brake wear, tyre wear and road-surface interaction. Moving traffic can also resuspend dust already present on the road.

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Their relative importance depends on the vehicle, fuel and driving conditions.

Nitrogen dioxide (NO2) is an air pollutant associated particularly with combustion processes and road traffic. High concentrations are commonly found near busy roads and densely trafficked urban areas.

Particulate matter consists of tiny solid particles or liquid droplets suspended in the air. Road traffic can produce particles from exhaust, brakes, tyres and road surfaces.

No. Carbon dioxide is primarily regulated as a greenhouse gas because of its contribution to climate change. Local air-quality pollution generally focuses on substances such as nitrogen dioxide, particulate matter, ozone and other pollutants that directly affect air quality and health.

Fully electric vehicles produce no combustion-engine exhaust emissions while driving, but they can still contribute to non-exhaust particulate emissions through tyres, brakes and road wear.

Yes. Concentrations of traffic-related pollutants can be higher close to heavily trafficked roads because many emissions occur close to ground level and near where people live and travel.

A low-emission zone is an area where access by more polluting vehicles is restricted in order to reduce traffic-related air pollution. Access criteria may depend on factors such as fuel type, vehicle category and emission standard.

Measures include cleaner vehicles, stricter emission standards, effective emission-control equipment, low-emission zones, public transport, cycling and walking, as well as traffic-management measures that reduce unnecessary congestion and emissions.

An interchange is a junction that allows traffic to transfer between major roads, commonly using ramps and grade-separated bridges or tunnels.

At an ordinary intersection, traffic streams normally meet or cross at the same level. An interchange usually separates major traffic movements vertically and connects them using ramps.

They are most common on motorways, expressways, ring roads and other high-capacity roads where stopping at ordinary intersections would disrupt traffic flow.

A ramp is a connecting road that allows vehicles to enter, leave or transfer between the roads forming the interchange.

Read the advance-direction signs early, identify your route or destination and move into the appropriate lane in sufficient time.

No. Interchanges can contain several exits and merging traffic streams. Signal in good time and change lane only when there is sufficient space to do so safely.

This depends on the local signs, markings and merging rules. Drivers joining a motorway commonly have to give way to traffic already travelling on it, but local regulations must always be followed.

Yes. Ramps may have lower speed limits or require a lower safe speed because of bends, merging traffic or limited visibility.

Continue to the next suitable exit or interchange. Never reverse, stop unexpectedly or cross prohibited areas to return to a missed exit.

No. Common layouts include cloverleaf, diamond, trumpet and directional interchanges. Their design depends on traffic volumes, available space and the roads being connected.

Rush hour is a period when unusually large numbers of people travel at the same time, resulting in increased traffic and often congestion.

Rush hour commonly occurs during the morning and late afternoon or evening on working days, but the exact times vary according to the city, road and local travel patterns.

No. The term does not mean that congestion lasts exactly one hour. In busy urban areas, peak traffic conditions may continue for several hours.

Congestion develops when traffic demand approaches or exceeds the available road capacity. Intersections, merging traffic, collisions, roadworks and weather can make the congestion worse.

Yes. Leave sufficient distance to react to sudden braking and frequent changes in traffic speed. Avoid following another vehicle too closely even when traffic is moving slowly.

Unnecessary lane changes can create additional conflicts and may not significantly reduce journey time. Choose an appropriate lane, observe surrounding traffic and change lane only when it can be done safely.

Yes. Roads equipped with variable traffic management may display lower speed limits during congestion. Drivers must follow the speed limit currently indicated.

A rush-hour lane is an additional traffic lane that can be opened during busy periods to increase road capacity. It may use a lane or shoulder that is closed to normal traffic at other times.

No. Such a lane may only be used when traffic signals or signs indicate that it is open. Never assume that congestion alone permits its use.

Check current traffic conditions and expected journey times, allow additional travel time and consider an alternative route, departure time or mode of transport where appropriate.

A filling station is a facility where vehicles can obtain petrol, diesel or other fuels and may also offer additional services for drivers and passengers.

Many countries use a service or information sign with a fuel-pump symbol to indicate a filling station. The exact design and meaning of the sign vary between countries.

Reduce your speed, follow the designated entrance and traffic direction and watch carefully for vehicles, pedestrians and people moving around the fuel pumps.

A road code is the body of traffic rules and regulations governing how road users must behave on public roads.

A road code can regulate subjects such as priority, speed, overtaking, turning, parking, traffic signals, road signs and road markings, as well as the responsibilities of different road users.

No. Although many traffic rules and signs are similar internationally, each country establishes its own traffic legislation and may apply different rules, signs, speed limits and requirements.

Two-way traffic means that vehicles may travel in both directions along the same road or carriageway.

They may be separated by centre lines, traffic lanes, a median or another physical divider. On some roads, opposing traffic may share an undivided carriageway.

Vehicles may approach from the opposite direction, so drivers should maintain a safe position and take particular care when overtaking, turning or passing through narrow sections.

A passing lane is a lane used primarily to overtake slower vehicles travelling in the same direction.

It depends on the country's driving side. In countries with right-hand traffic it is generally the left lane, while in countries with left-hand traffic it is generally the right lane.

The exact rules vary between countries, but drivers are commonly expected to return to the normal travel lane after completing an overtake when it is safe and required.

A street gutter is a drainage channel along the edge of a road that collects rainwater and directs it toward drains or another drainage system.

Normally, no. A gutter is primarily part of the road's drainage system and is not intended to function as a normal traffic lane.

Gutters may contain water, leaves, debris, drain covers or uneven surfaces, which can reduce grip or make cycling less stable.

Road debris is any object, material or substance lying on the road that may obstruct traffic or create a hazard.

Examples include lost cargo, vehicle parts, stones, branches, litter, broken glass and spilled materials.

Reduce speed when necessary, maintain control of your vehicle and avoid the debris only when you can do so safely. Avoid sudden braking or steering that could endanger other road users.