Road safety dictionary
Welcome to the Fundación Aleatica “Road Safety Terms Dictionary”. The purpose of this dictionary is to inform the general public of the terms and definitions used in the road safety and sustainable mobility field in order to increase awareness and knowledge about the importance of road safety on public roads.
In this dictionary, you will find a section of key terms related to road safety and sustainable mobility, accompanied by a brief and clear definition. This information will allow you to understand and effectively apply these terms in your daily life, whether it be as a driver, pedestrian, public transport user or any other role you may play as you transit through the public spaces of your street, city or country.
Road safety is a priority for Fundación Aleatica and we hope that this dictionary helps you understand and apply best practices to guarantee road safety on public roads. Thanks for visiting us and we hope that this tool is useful to you!
In addition to this initial section of terms, at Fundación Aleatica, we believe that the “Road Safety Terms Dictionary” can be a tool in constant evolution that is fed by the experiences and knowledge of users and road safety experts. We invite you to submit your recommendations and comments, to help us improve and expand this dictionary. We want this project to be useful to everyone and we’re counting on you to make that happen. Feel free to reach out!
This first version of the dictionary has been prepared by the team of specialists at Alianza Nacional por la Seguridad Vial (ANASEVI A.C.). We hope you find it very helpful in helping you have a better understanding of the fundamental terms used in this field. We also commit to keeping this dictionary up to date and continuing to expand it with terms to offer increasingly more complete and updated information.
Click on a letter to go directly to it. To return to this section, click on the large print in the first column.
ABS brakes
An anti-lock braking system that allows drivers to maintain directional control of the vehicle during emergency braking.
Accessibility
A set of measures aimed at ensuring equal access for persons with disabilities to the physical environment, transportation, information and communications—including information and communication technologies—and other services and facilities open or provided to the public.
Active safety
Set of standards and technologies aimed at avoiding traffic accidents, like braking systems, lighting, signs and horizontal and vertical signage.
Airbag
A passive safety device that activates during a collision to reduce injuries by absorbing the force of the impact.
Aquaplaning
Phenomenon that occurs when the tires of a vehicle lose contact with the pavement due to a layer of water on the highway, reducing braking capability and control of the vehicle.
Awareness
Transmission of information to the public, in order to raise awareness about use of the roadway and the problems that can arise there.
Blind spot
An area that is not visible to the driver through mirrors, where other vehicles or vulnerable road users may be present.
Braking distance
The distance a vehicle travels from the moment the brakes are applied until it comes to a complete stop. It increases with speed and adverse conditions.
Breathalyzer
An instrument used to measure the concentration of alcohol in exhaled breath. In Mexico, the legal limits are:
Private vehicle drivers: 0.25 mg/L (air) or 0.05 g/dL (blood)
Motorcyclists: 0.1 mg/L (air) or 0.02 g/dL (blood)
Public transport and freight drivers: zero alcohol.
BRT transport
A mass public transit system that uses high speed buses, exclusive lanes and pre-established stations for passenger boarding and deboarding.
Bus stop
Specifically marked location on a highway where busses pick up and drop off passengers.
Care-related mobility
Trips associated with unpaid caregiving work: transporting dependents, shopping, medical visits, among others. This type of mobility is often invisible and predominantly carried out by women.
Carpooling
A system in which multiple people share a single vehicle for the same route, aimed at improving efficiency, sustainability, and reducing costs.
Complete street
A roadway designed under principles of safe and accessible mobility that prioritizes pedestrians, cyclists, and public transportation, following universal design standards.
Construction zone
Area of a highway or road where construction or road work is being performed.
Counter direction
When a vehicle drives in the opposite direction than the established direction.
Curvature
Term that refers to the curve in a highway or road.
Cyclist
A person traveling by bicycle, either human-powered or with electric assistance.
Daytime running lights
Front lights that switch on automatically with the vehicle to improve visibility during daylight hours.
Defensive driving
Driving based on anticipating and preventing risks. It includes: maintaining safe distances, anticipating others’ mistakes, obeying traffic signs, avoiding distractions, and staying emotionally composed.
Discrimination based on disability
Any distinction, exclusion, or restriction that limits or prevents persons with disabilities from fully exercising their rights.
Distraction
Any element that diverts a driver’s attention, such as mobile phones, screens, conversations, food, among others.
Driver
An individual who has operational control of a vehicle in motion.
Emergency exits
Exit designed for use in case of emergency, especially in public transport or passenger vehicles.
Emergency lane
A side area on a highway reserved exclusively for emergency stops or the transit of assistance vehicles.
Emergency lights
Flashing lights of a vehicle used to indicate an emergency situation or a vehicle stopped on the highway.
Emergency vehicle
Vehicle used to respond to an emergency, like an ambulance or fire truck.
Escape route
Exit path identified for use in emergency situations.
Excess speed
Driving a vehicle at a speed over that permitted by law or over the speed that is safe for the road conditions.
Exclusive lane
A traffic lane reserved for specific types of vehicles (e.g., buses, bicycles, BRT) to enhance efficiency and safety.
Expressway / Freeway
A high-speed, controlled-access road designed exclusively for motor vehicles, with entry and exit via ramps or interchanges.
Following distance
A safe space that a driver should maintain between their vehicle and the one in front to avoid collisions in case of sudden braking.
Full stop (Mandatory stop)
A traffic sign indicating the driver must bring the vehicle to a full stop before proceeding, usually at intersections or pedestrian crossings.
Gender-sensitive awareness
The design and implementation of policies and programs that address structural inequalities between women and men in mobility.
Hazard lights
Flashing lights used to warn of danger, forced stops, or the presence of obstacles.
Highway
Fast speed roadway with restricted access, designed exclusively for the transit of motorized vehicles and with exchanges for access and exit.
Hybrid vehicle
Vehicle that uses more than one form of propulsion, generally with an internal combustion engine combined with an electric engine.
Hydroplaning
Loss of contact between the tires and the pavement due to water accumulation, which reduces vehicle control and increases crash risk.
Intersection
A point where two or more roads cross. It requires control through signage, traffic lights, or roundabouts to prevent conflicts.
Intersectionality
Recognition that a person may face multiple forms of inequality simultaneously (due to gender, age, ethnicity, disability, etc.), increasing their vulnerability in public space.
Lane
A longitudinal section of a roadway, marked or unmarked, intended for single-direction traffic flow.
Last mile delivery
The final stage of goods transportation from a logistics center to the end consumer. Critical to urban logistics.
Level crossings
Level intersections where the railway crosses the highway.
Load limit
The maximum authorized weight for a vehicle, including its own weight and the transported cargo.
Median
A physical divider that separates opposing traffic flows on a road.
Mobility
The capacity to move people and goods through public space using different modes (walking, cycling, motorized transport, etc.).
Mobility hierarchy
A principle guiding road design and planning by prioritizing the most vulnerable road users.
Mobility pyramid
Conceptual model that ranks the different methods of transportation based on their environmental impact and road safety. At the top of the pyramid are sustainable and safe methods, like walking or cycling, while at the bottom are more dangerous and polluting forms of transportation, like cars.
Mobility systems
The combination of infrastructure, vehicles, technologies, and regulations that enable the safe and efficient movement of people and goods.
Motorcycle
A motorized vehicle with two or more wheels, powered by either a combustion or electric engine. Includes scooters, trikes, ATVs, and others.
Overtaking
A maneuver in which one vehicle passes another moving in the same direction. Requires appropriate visibility and safety conditions.
Passing
A maneuver performed by a driver to move ahead of another vehicle moving in the same direction.
Passive safety
Systems that protect occupants in the event of a crash (seat belts, airbags, crumple zones).
Pedestrian
A person traveling on foot or using assistance devices (wheelchair, cane, walker, etc.). Also includes individuals on skates, skateboards, or pushing strollers or cargo.
Pedestrian collision
A road traffic incident in which a vehicle strikes a pedestrian, causing injury or fatality. It should not be referred to as an “accident” as it is preventable.
Pedestrian overpass
An elevated or underground structure that allows people to safely cross high-speed or multi-lane roads.
Pedestrianization
An urban measure that restricts or eliminates vehicular traffic in specific areas to prioritize pedestrian use.
Peripheral vision
A driving technique that uses indirect lateral vision to detect hazards without diverting one’s main focus from the road.
Photo radar fine
An economic fine levied against a violating driver, captured by photo and video cameras installed on public roads.
Priority (Right of way)
The legally recognized right of certain users or vehicles to proceed before others, as defined by signage or regulations.
Protective barrier
A physical structure installed to prevent vehicles from leaving the roadway and to reduce the severity of impacts.
Public road
A space for common use intended for transit, social interaction, or the provision of public services.
Public transport
A regulated collective service that transports people locally, regionally, or between cities.
Pylon
Road signage device used to define work or danger zones on the public road.
Rearview mirror
Mirror that allows the driver to see the vehicles or people who are behind the vehicle.
Residential zone
An urban area primarily used for housing, where pedestrian priority and reduced vehicle speeds are enforced.
Risk factor
An element or behavior that increases the likelihood of a road traffic crash. Examples include speed, alcohol, distraction, and poor visibility.
Road accident
Unexpected event that occurs on the public roadway and involves one or more vehicles, pedestrians or cyclists, and that may result in injuries or physical damages. This can be accurately referred to as a Road Mishap, as it is something unpredictable.
Road coexistence
An ethical principle of mutual respect among all road users, promoting a culture of collective care.
Road curvature
The degree to which a road deviates from a straight line. Poorly designed curves increase crash risk.
Road education
Activity aimed at promoting road culture among the population, targeted at all people who use the roadway, with the goal of generating change in social behavior patterns.
Road infrastructure
A set of physical and functional elements (roads, sidewalks, bike lanes, traffic signals, signage, pedestrian bridges) designed to ensure the safe movement of people and vehicles.
Road maintenance
A set of technical interventions aimed at preserving or improving road conditions to ensure safety and comfort.
Road network
The system comprising all interconnected roadways in a given area, including their physical structure, regulations, and operations.
Road Safety
A set of policies, actions, technologies, and behaviors aimed at preventing road traffic crashes and minimizing their consequences.
Road Safety Audits
Technical assessments applied to road infrastructure projects to identify and correct risks before crashes occur.
Road system
Comprehensive set of roadways in common use that comprise the urban area.
Road user
Any person using the road, whether as a pedestrian, cyclist, passenger, or driver, via motorized or non-motorized means.
Roadway
Physical space intended for the transit of pedestrians and vehicles.
Roundabout (Traffic circle)
A circular intersection where vehicles move around a central island. It facilitates smooth and safe traffic flow through orderly entry and circulation.
Safe school routes
Infrastructure and measures enabling children and adolescents to travel safely to and from educational centers—on foot, by bicycle, or via school transport.
Safe system
A coordinated set of strategies and policies that distribute responsibility for road safety among all stakeholders, prioritizing the reduction of deaths and serious injuries.
Safe systems
Effective, efficient and priority practices that redistribute responsibilities among all the different players involved in mobility rather than just the users, with risk-free roads, transport safety systems in vehicles and safe speeds being particularly relevant.
Safer vehicles
A safer vehicle (including motorcycles) is one that is designed, manufactured and assembled to protect the lives of its occupants and road users outside the vehicle. To this end, they must have safety features that reduce the likelihood of an incident and the severity of the consequences should an incident that could not be avoided occur.
Safety device
A system or mechanism intended to protect life, health, and physical integrity during travel. Examples: seat belt, helmet, airbag.
Safety helmet
Personal protective equipment that reduces the risk of head injuries. Mandatory for motorcycle users.
Safety perimeter
A clear area that must be maintained around vehicles or objects to ensure visibility and maneuverability.
Safety zone
A protected space for vulnerable users, especially pedestrians, using signage or physical barriers.
Seat belt
A device that secures vehicle occupants, reducing the risk of injury or death in the event of a crash.
Security zone
Designated area where pedestrians or vehicles are protected from other vehicles in motion, often using physical barriers.
Self-driving vehicle
Vehicle capable of driving and navigating on its own without human intervention.
Self-explaining roads
Roadways designed so that the intended behavior of drivers is intuitive, using visual elements, clear signage, and landscaping.
Service road
A secondary road built to provide access to nearby properties or to support the operation of a main road.
Shock absorbers
A component of a vehicle’s suspension system that reduces the impact caused by road surface irregularities.
Shocks
Part of a vehicle’s suspension that absorbs the impact and vibrations of the road.
Shoulder
Space along the side of a highway or road used for vehicles to stop in case of emergency.
Sidewalk
A designated space for pedestrian movement, typically located along the sides of a road.
Solid line
A road marking indicating a prohibition to change lanes or overtake, due to visibility or safety conditions.
Speed bump (Traffic calming device)
A physical element (hump, rumble strip, raised surface) designed to force vehicles to reduce speed.
Speed camera (Photo radar)
A fine issued via automated electronic devices (radars, cameras) that detect traffic violations without the presence of an officer.
Speed limit
Maximum speed permitted by law for driving on a public road.
Speed management
A set of regulatory, technological, urban, and educational measures aimed at ensuring vehicles travel at appropriate speeds to prevent serious injuries or fatalities in the event of a crash.
Speed radar
An electronic device that measures vehicle speed to detect infractions and issue fines.
Sustainable mobility
A mobility model that reduces the environmental and social impact of transport by promoting non-motorized modes, public transportation, and energy efficiency.
Systemic approach
Approach that addresses mobility as a whole on a comprehensive basis, in which a series of coordinated and interconnected elements interact.
Technical vehicle inspection
Periodic review that must be performed to vehicles to verify their mechanical, electrical and safety condition, and to ensure they comply with the requirements to drive on the public roadway.
Toll
Fee that must be paid to drive on a road or highway in order to fund its maintenance and improvement.
Toll evasion
Act of going through a toll collection point without paying the corresponding fee.
Towing service
Service responsible for removing vehicles that are stranded or have been in an accident on the public roadway.
Towing service
A service used to remove immobilized or crashed vehicles from the roadway to restore safe traffic conditions.
Traffic circle
Circular intersection where the vehicles driving around it have the right-of-way over those that want to access it.
Traffic claim
Any event, fact, accident or incident on the public roadway arising from the transit of vehicles or people, involving at least one vehicle and that causes death or injuries, including those causing a disability, or physical damages, that are preventable and the adverse effects of which can be lessened.
Traffic cone
A device used to mark construction zones, detours, or temporary hazards on the road.
Traffic control device
Set of signs, markings, various devices and other elements placed on roadways to prevent, regulate and guide the flow of pedestrians and vehicles that meet the universal design criteria, guaranteeing appropriate visibility at all times.
Traffic crash
An event on a public road involving at least one vehicle that results in death, injury (including disabilities), or property damage. It is preventable and should not be called an “accident.”
Traffic light
A signaling device that uses colored lights to regulate the movement of vehicles and pedestrians.
Traffic light coordination (Signal timing)
A system for regulating traffic flow through light signals (red, amber, green) to manage movement at intersections and pedestrian crossings.
Traffic management
Actions designed to organize, regulate, and control the movement of vehicles and people to enhance road safety and traffic efficiency.
Traffic regulations (Traffic code)
A set of legal provisions governing the movement of vehicles, pedestrians, and other road users on public roads. It establishes rights, obligations, and penalties.
Traffic sign
A device, marking, or indicator that informs, warns, or regulates the behavior of public road users.
Traffic signage
A set of permanent or temporary visual elements used to guide or regulate traffic (vertical, horizontal, luminous, or auditory).
Traumatic brain injury
A head injury resulting from a traffic crash, potentially affecting the scalp, skull, or brain.
Trips (Displacements)
The movement of a person from one origin to a destination for a specific purpose, using one or more modes of transportation.
Two-way traffic
A roadway where vehicles travel in opposite directions, typically separated by a center line.
Universal design
The design of products, services, and infrastructure that can be used by all people without the need for special adaptations. It does not exclude the use of assistive devices for persons with disabilities.
Urban construction zone (Construction zone)
An area where road maintenance, construction, or improvement work is underway—usually marked and subject to temporary restrictions.
Vehicle safety
Measures focused on the performance and protection offered by a motorized vehicle to passengers and users of a roadway against the risk of death or serious injury in the event of a traffic incident.
Vehicle safety devices
Safety devices installed in vehicles—like seatbelts and airbags—that protect the occupants in case of an accident.
Visibility
A road user’s ability to perceive their surroundings, influenced by lighting, weather conditions, signage, and obstacles.
Vulnerable groups
Populations facing greater barriers to exercising their right to safe mobility: persons with disabilities, children, adolescents, older adults, women, low-income individuals, Indigenous communities, and LGBTTTIQ+ people.
Vulnerable road users
Individuals at higher risk in traffic due to physical condition, age, or transport mode. Includes pedestrians, cyclists, motorcyclists, children, older adults, and persons with disabilities.
Yield (Give way)
A traffic sign indicating that drivers must allow other vehicles or pedestrians with right of way to proceed first.
Zebra crossing (Pedestrian crossing)
A repeated concept — consolidated under “Pedestrian crossing” in earlier entries.
Zone for loading/unloading
A reserved area for brief logistics operations without obstructing general traffic.
Zone near schools (School zone)
An area near educational centers where special speed reduction, signage, and enforcement measures apply.
Zone of low emissions (Low-emission zone)
An urban area where the circulation of polluting vehicles is restricted to improve air quality.
Zone of safety (Safety zone)
A protected space for vulnerable users, especially pedestrians, using signage or physical barriers.
Zone with pedestrian priority (Residential zone)
An urban area primarily used for housing, where pedestrian priority and reduced vehicle speeds are enforced.
