Señales de tráficoMéxico

A start-stop system automatically switches off the engine when the vehicle is stationary and restarts it when the driver is ready to continue.

The system is primarily intended to reduce unnecessary engine idling, particularly when a vehicle is waiting in traffic.

Not necessarily. The system may keep the engine running when operating conditions do not allow an automatic stop, depending on the vehicle and its systems.

A manual transmission is a gearbox in which the driver manually selects the appropriate gear, normally using a gear lever and clutch pedal.

The clutch temporarily disconnects the engine from the transmission, allowing the driver to start, stop and change gears smoothly.

With a manual transmission, the driver selects and changes gears. An automatic transmission normally selects the appropriate gears automatically without requiring a conventional clutch pedal.

An automatic transmission is a gearbox that automatically selects and changes gears without requiring the driver to operate a conventional clutch pedal.

With an automatic transmission, gear changes are handled automatically, while a manual transmission normally requires the driver to operate a clutch and select each gear manually.

No. Different designs include conventional automatic transmissions, continuously variable transmissions and dual-clutch systems, although they can all operate without the driver manually controlling a clutch during normal driving.

A throttle is a control that regulates how much power an engine or motor produces.

In most cars, the throttle is controlled using the accelerator pedal. Motorcycles and some other vehicles commonly use a twist-grip throttle.

They are closely related but not exactly the same. The accelerator is the driver's control, while the throttle refers more broadly to the system that responds to that input and regulates engine or motor power.

A tachometer is an instrument that measures and displays the rotational speed of an engine or motor, usually in revolutions per minute.

RPM means revolutions per minute and indicates how many complete rotations the engine's crankshaft makes in one minute.

No. A tachometer shows engine rotational speed, while a speedometer shows the vehicle's road speed.

A steering wheel is the driver's main control for changing the direction in which a vehicle travels.

Turning the steering wheel operates the vehicle's steering system, which changes the direction of the steered wheels.

Normally, no. Steering should be smooth and controlled because sudden movements can destabilise the vehicle or create danger for other road users.

Power steering is a system that assists the driver's steering effort, making the steering wheel easier to turn.

Vehicles may use hydraulic, electro-hydraulic or electric power steering, depending on their design.

Steering may become considerably heavier or a warning may appear. The driver should maintain control, reduce speed safely and have the steering system checked as soon as possible.

Scanning means continuously observing different parts of the traffic environment so that hazards and changes can be detected early.

A driver should regularly observe the road ahead, mirrors, intersections, side areas, vulnerable road users and relevant blind spots.

Scanning helps drivers identify hazards earlier and gives them more time to adjust speed, position or direction safely.

A vehicle mirror allows the driver to observe traffic and other road users behind or beside the vehicle.

An interior rear-view mirror normally provides a view through the rear window, while exterior side mirrors provide views along the sides and towards the rear of the vehicle.

Check your mirrors regularly and particularly before changing speed or direction, changing lane, overtaking, merging, turning or stopping.

Yes. Mirrors should be adjusted from the normal driving position before setting off so that they provide the intended view of traffic behind and beside the vehicle.

No. Even correctly adjusted mirrors can leave areas that are not visible to the driver. These are commonly called blind spots.

Yes. Where necessary, use a brief direct observation in addition to the mirrors before moving sideways so that a cyclist, motorcycle or other vehicle hidden from the mirrors is not overlooked.

Yes. A cracked, loose, missing or badly adjusted mirror can reduce the driver's view of surrounding traffic and should be repaired or replaced when necessary.

Some vehicles use approved camera-based indirect-vision systems instead of or in addition to conventional mirrors. Whether such a system is legally permitted depends on the vehicle's approval and local technical requirements.

Checking the mirrors can help detect cyclists, motorcyclists and other approaching road users before a door is opened into their path.

Yes, according to the applicable vehicle requirements. Motorcycles normally have one or more rear-view mirrors so that the rider can observe traffic behind without turning around for extended periods.

Common fuels include petrol, diesel, LPG and CNG. Some vehicles can also use biofuels or other alternative fuels, while electric vehicles obtain their energy from a battery rather than conventional fuel.

Check the vehicle manufacturer's instructions and the fuel information shown near the filler opening or on the vehicle. Fuel pumps are normally labelled to help drivers identify compatible fuels.

Smooth acceleration, anticipating traffic, maintaining an appropriate speed, correct tyre pressure, avoiding unnecessary loads and keeping the vehicle properly maintained can help reduce fuel consumption.

A fuel gauge shows the approximate amount of fuel remaining in the vehicle's tank. Most gauges use a scale between empty and full.

The low-fuel warning light indicates that the amount of fuel remaining has reached a low level. The driver should refuel soon rather than relying on the remaining reserve.

No. A fuel gauge provides an approximate reading. The indicated level can vary because of vehicle movement, road gradient, tank shape and the design of the fuel-level sensor.

Petrol is a liquid motor fuel used mainly in spark-ignition engines. It is called petrol in many countries and may contain ethanol or other renewable components.

The octane rating indicates the fuel's resistance to uncontrolled combustion or engine knocking. Vehicles should use petrol with at least the octane rating specified by the manufacturer.

E5 and E10 indicate the permitted ethanol content of petrol. E5 contains up to 5% ethanol by volume, while E10 contains up to 10%. Drivers should check whether their vehicle is compatible with the selected fuel.

Diesel is a liquid motor fuel designed primarily for compression-ignition engines. These engines compress air until it becomes hot enough to ignite the injected fuel.

The letter B identifies diesel containing biodiesel components. The number indicates the maximum percentage of biodiesel in the fuel, so B7 may contain up to 7% and B10 up to 10% biodiesel.

No. Compatibility depends on the vehicle and engine. Drivers should follow the manufacturer's specifications before using fuels such as B10, higher biodiesel blends or synthetic diesel.

Diesel exhaust fluid is used in vehicles equipped with an SCR system. It is injected into the exhaust gases to help reduce nitrogen oxide emissions produced by the diesel engine.

No. Diesel exhaust fluid is not a fuel and must never be poured into the diesel tank. Vehicles that use it have a separate DEF tank, usually identified by a dedicated filler cap.

Refill the DEF tank with fluid that meets the specification required by the vehicle manufacturer. Do not ignore the warning, because some vehicles can restrict operation or prevent restarting if the DEF supply becomes empty.

Coverage depends on the policy. Liability insurance generally covers injury or damage caused to other people, while optional forms of insurance may also cover damage to the insured vehicle, theft, fire or other risks.

Many countries require at least a minimum level of motor liability insurance before a vehicle may be used on public roads. The exact requirements and exemptions depend on national law.

Liability insurance primarily covers damage or injury for which the insured driver is legally responsible toward others. Comprehensive or similar optional cover can also protect the insured vehicle against risks such as theft, fire, vandalism or accidental damage, depending on the policy.

A first aid kit provides basic materials that can be used to treat injuries or control bleeding while waiting for professional medical assistance.

No. Requirements vary between countries and vehicle types. Some countries require motorists to carry an approved first aid kit, while others only recommend having one.

Yes. Its contents should remain complete, clean and usable. Used items should be replaced, and products with expiry dates should be checked periodically.

A fire extinguisher can help control a small fire before it spreads, provided it is safe to use. If a fire is already large or spreading rapidly, occupants should move away from the vehicle and contact the emergency services.

No. Requirements vary between countries and vehicle types. Some countries require extinguishers in passenger cars or particular commercial vehicles, while others only recommend carrying one.

It should be securely mounted in an accessible location and protected from damage. Drivers should also check its condition, seal and expiry or service information according to the applicable requirements.

High-visibility clothing is designed to make the wearer more noticeable to other road users. Safety vests typically combine fluorescent material for daytime visibility with retro-reflective material that becomes particularly visible when illuminated at night.

It should be worn whenever leaving a vehicle in a situation where approaching traffic could present a danger, particularly after a breakdown or emergency and in conditions of poor visibility.

This depends on the country. Some countries require a reflective vest to be carried in the vehicle and worn in specified breakdown or emergency situations, while others only recommend it.

First aid aims to preserve life, prevent an injury or illness from becoming worse and provide appropriate immediate care until professional medical assistance becomes available.

First check that it is safe to approach. Assess the casualty, contact the emergency services when necessary and provide appropriate assistance within your level of knowledge and training.

No. An injured person should generally not be moved unnecessarily because movement can worsen certain injuries. Moving the casualty may be necessary when remaining in the location creates an immediate danger, such as fire or approaching traffic.

A concrete step barrier is designed to contain or redirect a vehicle that leaves its intended path. It can be used to separate opposing traffic or protect road users from dangerous areas beside the roadway.

Both are concrete vehicle-restraint barriers, but they use different cross-sectional profiles. A step barrier has a stepped-profile face, while a Jersey barrier uses the characteristic Jersey-shaped sloping profile. Their actual safety performance depends on the tested barrier system rather than simply on its shape.

No. Step barriers can be constructed as continuous cast-in-place barriers or as prefabricated concrete sections, depending on the particular road-restraint system and installation.

Road barriers can close roads or lanes, control access, separate traffic streams, protect work zones and prevent vehicles from entering hazardous or restricted areas.

Yes. Temporary barriers are commonly used during roadworks, emergencies and special traffic arrangements, while permanent barriers may be installed for access control or long-term protection.

No. A closed barrier normally indicates that access is prohibited or unsafe. Drivers should stop and follow any accompanying signs, signals or instructions rather than attempting to drive around it.

Common vehicle lights include dipped-beam and main-beam headlights, position lights, daytime running lights, rear lights, brake lights, direction indicators, reversing lights, fog lights and hazard warning lights.

Dipped-beam headlights are normally used at night and whenever visibility is poor. Unlike main beams, they are designed to illuminate the road while reducing glare for other road users.

Main beams should be changed to dipped beams whenever they could dazzle approaching or preceding road users. The precise requirements and distances vary between countries.

Street lights improve visibility during darkness and can help road users see the road layout, intersections, pedestrians, cyclists, obstacles and other traffic more clearly.

Usually yes. Street lighting does not normally replace the vehicle-lighting requirements that apply at night or in poor visibility. Drivers must follow the lighting rules of the country in which they are driving.

Main beam should not be used when it could dazzle other road users, and many countries require dipped beam instead on sufficiently illuminated roads. Drivers should use the appropriate lighting for the road and traffic conditions.

Dipped beam is the normal low-beam headlight setting. It illuminates the road in front of the vehicle while limiting glare towards approaching and preceding road users.

Dipped beam is generally used during darkness, in reduced visibility and whenever main-beam headlights could dazzle another road user. Exact requirements vary between countries.

Dipped beam directs light lower and is suitable when other traffic is present. Main beam projects light farther ahead but must be switched off when it could dazzle other road users.

High beam provides long-range illumination and can help a driver see farther ahead on dark roads where there is little or no other traffic.

You should switch to dipped beam whenever high beam could dazzle approaching or preceding road users. Exact requirements and distances vary between countries.

Often not when the existing road lighting already provides sufficient visibility. National traffic rules may specifically require dipped beam instead in adequately illuminated areas.