Señales de tráficoMéxico

Air conditioning cools and dehumidifies the air inside the vehicle, helping improve comfort and reduce moisture on the windows.

Yes. Because air conditioning removes moisture from the air, it can help clear condensation from the windscreen and windows more quickly.

Yes. Air conditioning can still be useful in winter because it reduces humidity inside the vehicle and can help demist the windows.

Yes. Operating the air-conditioning system requires energy and can increase fuel or electricity consumption, although the effect depends on the vehicle, system and conditions.

Yes. Regular use and maintenance can help keep the system effective. A poorly functioning system may cool less efficiently or fail to remove moisture properly.

Yes, in many vehicles and countries air conditioning itself is not required. However, the driver must still maintain adequate visibility and safe conditions inside the vehicle.

Hydroplaning occurs when water separates the tyres from the road surface, reducing or temporarily removing normal tyre grip.

The risk increases with higher speed, standing water, worn tyres and insufficient tyre tread. Tyre pressure and road conditions can also affect the risk.

Reduce speed in heavy rain, avoid driving through deep standing water where possible and keep your tyres properly maintained with sufficient tread depth.

Remain calm, ease off the accelerator and avoid sudden braking or steering. Keep the steering movements smooth and controlled until the tyres regain contact with the road.

Yes. Tyre grooves help move water away from the contact area. Worn tyres can remove less water, increasing the risk of losing grip on a wet road.

There is no single speed at which hydroplaning always begins. The risk depends on speed, water depth, tyre condition, tyre pressure and the road surface.

Distracted driving occurs when a driver's visual, manual or mental attention is diverted from driving and the surrounding traffic.

Common distractions include mobile phones, navigation systems, passengers, eating, adjusting vehicle controls and looking away from the road.

Using a phone can combine visual, manual and mental distraction, reducing the driver's ability to notice hazards and react quickly.

Yes. Even when the driver's hands remain on the wheel, a conversation can create mental distraction and reduce attention to traffic.

Yes. Entering destinations or repeatedly looking at a screen can divert attention from the road. Set the route before driving whenever possible and use voice guidance where helpful.

Prepare navigation and vehicle settings before moving, secure loose objects, keep your phone away from unnecessary use and focus continuously on the road and traffic.

Yes. Strong emotions can affect attention, judgement, reaction time and decision-making, which can make safe driving more difficult.

Anger can lead to impatience, aggressive manoeuvres, speeding or reduced attention. Drivers should avoid reacting emotionally to other road users.

Yes. Stress can make it harder to focus on traffic and process information calmly, especially in complex or busy situations.

If your emotional state is affecting concentration or judgement, stop or delay the journey when possible and continue only when you feel able to drive safely.

Yes. Positive emotions such as excitement can still reduce concentration or encourage impulsive behaviour if they take attention away from driving.

Allow enough travel time, avoid reacting to aggressive drivers, keep a safe distance and take a break when stress or frustration becomes difficult to manage.

Road rage is aggressive, hostile or intimidating behaviour directed at other road users, often caused by anger or frustration in traffic.

Examples can include tailgating, excessive honking, shouting, threatening gestures, deliberately blocking another vehicle or aggressive overtaking and lane changes.

Anger can reduce judgement and encourage impulsive or risky driving, increasing the chance of collisions and escalating conflicts between road users.

Stay calm, avoid confrontation, maintain a safe distance and do not retaliate or copy the other driver's behaviour. If necessary, move away from the situation when it is safe to do so.

Generally, no. Confrontation can make the situation more dangerous. It is usually safer to remain in your vehicle and create distance from the aggressive road user.

Allow enough travel time, accept that other road users make mistakes, avoid competing for road space and focus on reaching your destination safely rather than reacting emotionally.

Health problems can affect vision, concentration, reaction time, judgement, coordination and vehicle control, making safe driving more difficult.

Not if the illness makes it difficult to concentrate, react quickly or control the vehicle safely. Drivers should delay the journey or seek medical advice when necessary.

Yes. Some medicines can cause drowsiness, dizziness, blurred vision or slower reactions. Always follow the instructions provided with the medicine and advice from a healthcare professional.

Yes. Good vision is essential for recognising traffic signs, road users, hazards and changes in traffic conditions. Many countries set minimum eyesight requirements for drivers.

Yes. Depending on the country and condition, a driver may need a medical assessment, licence restriction or adapted vehicle before being permitted to drive.

This depends on local law. The driver usually has a responsibility to ensure they are fit to drive, while doctors or specialised assessment centres may evaluate driving fitness when required.

Yes. A seizure can cause loss of awareness, consciousness or vehicle control, so epilepsy can affect whether a person is medically fit to drive.

In many countries, yes, provided specific medical and seizure-free requirements are met. The exact conditions depend on the country, licence category and individual medical situation.

Do not assume it is safe to continue driving. Seek medical advice and check the applicable driving-licence rules, because a temporary period without driving may be required.

A seizure-free period helps assess the risk of another seizure occurring while driving. The required period varies depending on the type and cause of the seizure and local regulations.

Yes. Anti-seizure medicines can sometimes cause effects such as drowsiness, dizziness or reduced concentration. Changes in treatment can also affect seizure control, so medical advice should be followed.

Usually, yes. Drivers of trucks, buses and vehicles used for certain professional transport generally face stricter medical fitness requirements because of the greater potential consequences of a seizure while driving.

Night blindness is difficulty seeing in darkness or low-light conditions, even when daytime vision may be relatively good.

It can make pedestrians, cyclists, road edges, signs and obstacles harder to detect, reducing the time available to react safely.

No. Night blindness usually means reduced vision in dim conditions, not a complete loss of sight.

Possible causes include retinal disorders, cataracts, certain inherited eye conditions and some nutritional deficiencies. An eye-care professional can determine the underlying cause.

Glasses may help when poor low-light vision is partly caused by an uncorrected refractive error, but not every cause of night blindness can be corrected with glasses.

If your low-light vision is not sufficient for safe driving, you should avoid driving at night or in other dark conditions and seek medical advice.

Visual impairment can make it harder to recognise signs, detect pedestrians and vehicles, judge distance and speed or see hazards in time.

Important visual functions include visual acuity, field of vision, contrast sensitivity, depth perception and the ability to see in changing light conditions.

Yes, provided your corrected vision meets the applicable legal standards. If your licence requires glasses or contact lenses, they must be used while driving.

In some countries, yes, provided the person meets specific visual-acuity, visual-field and adaptation requirements. The exact rules vary between countries.

Yes. Depending on the impairment, a licence may include conditions such as mandatory glasses, daytime-only driving, geographic restrictions or other limitations.

If your vision changes significantly or may no longer meet the required standards, seek an eye examination and medical advice before continuing to drive.

Fatigue can slow reaction time, reduce concentration and impair judgement, increasing the risk of missing hazards or losing control of the vehicle.

Warning signs include frequent yawning, heavy eyelids, difficulty concentrating, drifting within the lane and forgetting parts of the journey.

A microsleep is a very brief episode of sleep that can last only a few seconds. During that time, the driver may be completely unaware of the road and unable to react.

Stop at a safe place and rest before continuing. If possible, take a short nap or end the journey until you are sufficiently rested.

Caffeine may temporarily improve alertness, but it does not replace adequate sleep. A tired driver should still stop and rest.

Fatigue is more likely after long periods of driving, insufficient sleep, night driving or driving during normal sleeping hours.

A vehicle defect is a fault, damage or excessive wear that affects the condition, operation, safety or legal compliance of a vehicle.

Common defects include worn tyres, faulty lights, damaged brakes, steering problems, cracked windows, suspension faults and damaged electrical components.

No. Some defects are minor, while others can seriously affect braking, steering, visibility or vehicle control. The severity depends on the component and type of fault.

Assess whether the vehicle can still be driven safely and have the defect repaired as soon as possible. Do not continue driving if the defect creates a serious safety risk.

Yes. Dashboard warning lights can indicate faults involving systems such as the engine, brakes, airbags, tyre pressure or electrical system. The vehicle manual explains the meaning of each warning.

Yes. Periodic vehicle inspections are designed to identify technical and safety defects. The consequences depend on the type and severity of the defect and the applicable inspection rules.

A traffic violation occurs when a road user fails to follow an applicable traffic law, regulation, sign, signal or instruction.

Common violations include speeding, failing to stop, ignoring traffic lights, illegal parking, unsafe overtaking, using a phone while driving and failing to wear a seat belt.

No. Traffic offences are often divided into different levels of seriousness, with higher penalties for behaviour that creates a greater risk to road safety.

Depending on the country and offence, penalties can include fines, penalty points, driving bans, licence suspension, vehicle restrictions or court proceedings.

Yes. Traffic laws and penalties vary between countries, even when the underlying behaviour, such as speeding or using a mobile phone, is similar.

Yes. Serious or repeated offences can lead to a temporary or longer driving ban, depending on the applicable law and circumstances.

Alcohol can reduce reaction time, judgement, concentration, coordination and vision, increasing the risk of making mistakes or failing to react to hazards.

Blood alcohol concentration (BAC) measures the amount of alcohol in the blood. Legal driving limits are commonly expressed as a blood-alcohol level or as the concentration of alcohol in exhaled breath.

No. Alcohol limits vary between countries, and some countries apply lower or zero limits to novice, young or professional drivers.

Yes. Alcohol can affect driving ability even below the legal limit. A legal limit is not a guarantee that a person is safe to drive.

No. These may change how awake you feel, but they do not quickly remove alcohol from the body. Only time allows the body to eliminate alcohol.

Yes. Alcohol may remain in the body for many hours, so a person can still be over the legal limit or impaired the following morning.

An alcohol control is a police check used to determine whether a driver has consumed alcohol and whether the applicable legal limit has been exceeded.

Police commonly use a breath-testing device. Depending on the result and local procedure, a more precise breath analysis or blood test may follow.

In many countries, yes. Police may conduct random or routine alcohol checks without first observing obvious signs of intoxication.

Rules vary by country, but refusing a legally required alcohol test can itself be an offence and may result in penalties or an immediate driving restriction.

Yes. A blood test may be used when breath testing is impossible, disputed or required by the applicable legal procedure.

Yes. If the result exceeds the applicable limit, authorities may impose an immediate temporary driving prohibition in addition to any later fine, licence suspension or court proceedings.

An ignition interlock device is a breath-testing system connected to a vehicle that prevents the engine from starting when the driver’s alcohol concentration exceeds the programmed limit.

Before starting the vehicle, the driver provides a breath sample. If the alcohol concentration is below the permitted threshold, the vehicle can be started.

Some systems require additional breath tests during a journey to confirm that the authorised driver remains compliant. The exact procedure depends on the device and applicable rules.

Yes. Many systems can record breath-test results, failed attempts, events and possible attempts to interfere with the device.

Depending on the country, an ignition interlock may be required for drivers convicted of serious or repeated alcohol-related driving offences.

No. Having another person provide the breath sample defeats the purpose of the system and may be treated as tampering or non-compliance under the applicable rules.

A breath test is a preliminary test that detects alcohol in exhaled breath and indicates whether the alcohol level is below or above specified thresholds.

The person blows into a portable breath-testing device, which analyses a sample of exhaled air for alcohol.

No. A breath test is generally a screening test, while a breath analysis provides a more precise measurement of the alcohol concentration in exhaled breath.

Depending on local law, a positive result may be followed by a breath analysis, blood test or other evidential procedure.

In many countries, police may conduct roadside alcohol checks even when a driver does not show obvious signs of impairment. The exact powers vary by country.

Rules vary between countries, but refusing a legally required breath test can itself lead to penalties or an immediate restriction on driving.

A breath analysis measures the concentration of alcohol in exhaled breath using an approved evidential device.

No. A breath test is generally used for preliminary screening, while a breath analysis provides a more precise measured alcohol concentration.

The person blows into an approved breath-analysis device, which measures the alcohol concentration in the exhaled air.

The result is commonly expressed as milligrams of alcohol per litre of exhaled breath. The units and legal thresholds depend on the country.

Depending on local law, the result can lead to a temporary driving prohibition, fine, licence restriction or court proceedings.

In some countries, the person may have a right to a second breath analysis, blood test or other counter-analysis. The procedure depends on local law.

Blood alcohol content (BAC) measures the concentration of alcohol in a person’s blood and is used to assess alcohol consumption and legal driving limits.

BAC can be expressed as a percentage, grams of alcohol per litre of blood or parts per thousand (‰). The units commonly used depend on the country.

A BAC of 0.5‰ means 0.5 grams of alcohol per litre of blood, which is equivalent to 0.05% BAC.

No. BAC measures alcohol in the blood, while a breath test or breath analysis measures alcohol in exhaled air. Legal systems may establish corresponding limits for both measurements.

No. BAC can be influenced by factors such as body composition, sex, the amount and speed of drinking, food intake and the time since alcohol was consumed.

Yes. Alcohol can impair driving ability before the legal limit is reached. Being below the legal BAC limit does not guarantee that a person is safe to drive.

An alcohol blood test measures the concentration of alcohol in a blood sample and provides a blood alcohol concentration (BAC).

A blood test measures alcohol directly in the blood, while a breath analysis measures alcohol in exhaled breath. Both can be used to determine whether a legal alcohol limit has been exceeded.

A blood sample used for legal testing is normally taken by an authorised healthcare professional and analysed according to an approved procedure.

Depending on local law, a blood test may be used when breath testing cannot be performed, after certain accidents or as a counter-analysis of a breath result.

Blood alcohol concentration is commonly expressed as grams of alcohol per litre of blood, parts per thousand (‰) or a percentage, depending on the country.

Yes. In countries where a blood sample can lawfully be required, refusing without a legally accepted reason may itself be an offence.

A saliva test is a screening test that uses oral fluid to detect the recent presence of certain drugs or their metabolites.

A sample of saliva is collected from inside the mouth and tested using an approved portable device. The exact procedure and substances tested depend on the country.

No. A saliva test is generally a preliminary roadside screening, while a saliva analysis is a laboratory examination used to confirm and measure specified substances more precisely.

Depending on local law, a positive result can lead to a saliva analysis, blood test, temporary driving prohibition or further legal proceedings.

No. Saliva tests are designed to detect specific substances. The drugs included and the detection thresholds depend on the testing device and applicable law.

Rules vary between countries, but refusing a legally required saliva test can itself lead to penalties or an immediate restriction on driving.

Drugs can impair concentration, perception, reaction time, coordination and judgement. The effects depend on the substance, dose, individual and whether other substances are also present.

Yes. Cannabis can affect attention, reaction time, coordination and perception, which can make driving unsafe.

Yes. Stimulants can cause overconfidence, agitation, impulsive behaviour and reduced judgement, while their effects may later be followed by fatigue or reduced concentration.

Yes. Some substances can continue to affect alertness, coordination or judgement after the strongest effects appear to have passed.

Yes. Combining substances can produce stronger or unpredictable impairment and significantly increase the risk of a crash.

Depending on the country, police may use behavioural observations, saliva tests, saliva analyses or blood tests to detect specified substances.

No. Some countries prohibit driving above specified drug concentrations, while others focus on impairment or the presence of certain substances. Testing procedures and penalties also vary.

Yes. Some medicines can cause drowsiness, dizziness, blurred vision, slower reactions or reduced concentration, which can make driving unsafe.

Yes. A medicine can be legally prescribed and still impair your ability to drive safely. Follow the instructions provided by your doctor, pharmacist and patient information leaflet.

Yes. Medicines available without a prescription can also affect driving. Some antihistamines, cough medicines and other common products may cause drowsiness or other side effects.

Read the patient information leaflet, especially the section about driving and using machines, and ask a doctor or pharmacist if you are unsure.

Be especially cautious when starting a new medicine or changing the dose, because you may not yet know how it affects your alertness, coordination or judgement.

Yes. Alcohol can interact with some medicines and increase drowsiness, dizziness or other impairing effects. Follow the medicine instructions and professional medical advice.

A traffic penalty is a legal consequence imposed when a road user violates an applicable traffic law or regulation.

Penalties can include fines, penalty points, driving bans, licence suspension, vehicle restrictions and court proceedings. The available sanctions depend on the country.

Generally, yes. Traffic systems often apply heavier penalties to offences that create greater danger, involve excessive speed, impaired driving or repeated violations.

Yes. Many countries apply stronger sanctions to repeat offenders, such as higher fines, longer driving bans or mandatory rehabilitation measures.

Yes. Serious offences can result in a temporary or longer disqualification from driving, depending on the applicable law and circumstances.

No. Fine amounts, penalty-point systems, driving bans and enforcement procedures vary between countries.

Speeding means driving faster than the applicable maximum speed limit.

Higher speeds reduce reaction time, increase stopping distance and increase the severity of a collision.

Yes. A speed limit is normally a maximum. Drivers may need to drive more slowly because of traffic, weather, visibility or road conditions.

Authorities may use fixed or mobile speed cameras, radar, laser equipment, average-speed checks or police measurements, depending on the country.

Usually, yes. Many countries impose higher fines or additional penalties for larger speed-limit violations.

Yes. Serious or repeated speeding offences can lead to a driving ban, licence suspension or court proceedings, depending on local law.

Yes. Lighting, holding or extinguishing a cigarette can create manual and visual distraction, while smoke or dropped ash can also interfere with concentration.

This depends on the country. Some countries allow smoking while driving but prohibit it when children are present or in certain types of vehicles.

Smoking in an enclosed vehicle exposes passengers to second-hand smoke, and children are particularly vulnerable to its harmful effects.

In some countries, yes. Laws may treat vaping or electronic cigarettes in the same way as smoking when restricting their use inside vehicles.

Heavy smoke inside a vehicle can reduce comfort and visibility, while smoke residue can also create a film on the windscreen and windows that increases glare.

Yes. A discarded cigarette can create litter, distract other road users or start a fire, particularly in dry vegetation.