ITS in a nutshell

You are welcome to read about connected driving scenarios (applications) in this section. You can find short descriptions and illustrations or user interface examples of the following scenarios:

  • Access to premises
  • Accident Warning, Vehicle Emergency Response
  • Blind Spot Warning
  • Broken Down Vehicle warning
  • Control Loss Warning
  • Curve Speed Warning
  • Do Not Pass Warning
  • Emergency Electronic Brake Light
  • Emergency Vehicle Alert
  • Forward Collision Warning, Pre-crash Actions
  • Hazardous Location Warning, Situational Awareness
  • Intersection Movement Assist
  • In-Vehicle Signage
  • Lane Change Assist
  • Oversize Vehicle Warning
  • Overtaking Vehicle Warning
  • Platooning
  • Railroad Crossing Violation Warning
  • Red Light Violation
  • Reduced Speed Zone/Lane Closure Warning
  • Restricted Lane Warning
  • Roadside Alert, Warnings about upcoming Workzone/ Hazards in a Work Zone
  • Slow/Stationary Vehicle Warning
  • Smart Parking [Traveller information System]
  • Stop Sign Gap Assist
  • Stop Sign Violation Warning
  • Tailgating Advisory
  • Time-to-Green & GLOSA
  • Traffic Signal Priority Request/Preemption
  • Transit Vehicle at Station/Stop Warnings
  • (Right/Left) Turn Assist
  • Vehicle Turning Right in Front of a Transit Vehicle
  • VRU Protection
    • Bicycle/Motorcycle Approaching
    • Pedestrian Crossing Warning, Transit Bus Stop Pedestrian Warning
  • Wrong-Way Driver Detection & Warning
Access to Premises

Authenticated Access to Premises can be carried out via Vehicle-to-Everything (V2X) communication. When a connected vehicle wants to access a restricted area, it sends a signal about its intention to the digital infrastructure of the area. The vehicle then receives an authentication request and the driver provides authentication data.

Accident Warning, Vehicle Emergency Response

If a (connected) vehicle has but had an accident, an Accident Warning is sent to connected vehicles in the relevant zone via V2V-communication. Vehicle Emergency Response application allows connected vehicles sent accident-relevant information (such as HAZMAT data, type of vehicle, information about airbag activations) to the emergency responders so that the latter can act efficiently.

Blind Spot Warning

When vehicle A (blue in the picture) enters the blind spot of vehicle B (white in the picture) driving ahead, vehicle A sends a warning signal to vehicle B via V2V-communication.

Broken Down Vehicle Warning

If a connected vehicle breaks down, it communicates the alert to connected vehicles in the relevant zone. An alternative scenario includes a non-connected broken-down vehicle that is detected by a connected vehicle, and the latter transmits the corresponding warning further.

Control Loss Warning

When control over the vehicle is lost (red cars in the picture – due to aquaplaning), the vehicle sends a self-generated loss of control warning via V2V-communication to other vehicles that are in the danger zone (white car in the picture). Upon receiving the information, the receiving vehicle decides on the relevance of the event and, if necessary, issues a warning to the driver. When the vehicles communicate further in order to find a good solution together, one speaks of cooperative driving, or more precisely Cooperative Collision Avoidance.

Curve Speed Warning

The application provides connected vehicles with the information about approaching a curve and recommended speed for the curve. It warns the driver if the actual speed through the curve exceeds the recommended speed.

Do Not Pass Warning

When vehicle A (white in the picture) starts an overtaking maneuver, the oncoming vehicle B (red in the picture) sends a signal via V2V-communication that the passing zone is occupied. With this warning, the driver of vehicle A knows that a vehicle is coming towards him and aborts overtaking.

Emergency Electronic Brake Light

Vehicle A (blue in the picture) suddenly brakes hard because of an obstacle in front of it. The vehicle broadcasts a self-generated emergency brake event via V2V-communication to surrounding vehicles. Upon receiving the event information, vehicle B (white in the picture) determines the relevance of the event and if appropriate warns the driver so that she can react accordingly, even when she does not see the obstacle herself.

© Andreas Schlichter
Emergency Vehicle Alert

The driver of a connected vehicle receives a warning about an approaching emergency vehicle and its location so that the emergency corridor could be formed promptly and efficiently.

Forward Collision Warning, Pre-crash Actions

Vehicle A (red in the picture) stops, drives slower, or pulls in ahead of Vehicle B (white in the picture), creating a risk of a rear-end collision. The driver of vehicle B receives a warning via V2V-communication and can be advised to take specific actions in order to avoid or mitigate the forward collision if it is no longer unavoidable. If the accident is unavoidable, the Pre-Crash Actions application activates safety countermeasures, for example, emergency brake assist, airbag pre-arming, or seat belt tensioning.

Hazardous Location Warning, Situational Awareness

In V2I scenario, an ITS Roadside Station issues alerts of unsafe road conditions (due to weather or other reasons, e.g. water, ice, or a pothole on the road), which are communicated to approaching connected vehicles. Such warnings can be also accompanied by diversion information or speed recommendations.

In V2V scenario (Situational Awareness), the information about hazardous locations on the road is exchanged between the vehicles.

Intersection Movement Assist

When two (or more) connected vehicles are approaching an unsignalized intersection, they receive notifications about each other and collision warning information (Intersection Collision Warning) so that the drivers can act accordingly. The application also warns the driver of an approaching connected vehicle if another vehicle is performing an unexpected action (e.g., a sudden turn).

In-Vehicle Signage

The application delivers information to drivers directly via in-vehicle systems and therefore augments road signs and signals.

The driver of a connected vehicle can receive both static sign information (e.g., curve warning or directional signs) and dynamic information (e.g., current lane availability and the speed limit on a highway).

Lane Change Assist

When vehicle A (white in the picture) wants to perform a lane change maneuver and vehicle B (red in the picture) approaches the area to which vehicle A would pull in, the latter receives a warning from vehicle B via V2V-communication. The application also includes the option when vehicle A sends a signal to vehicle B to ask for letting it merge onto a highway in front of vehicle B.

Oversize Vehicle Warning

The application allows a connected vehicle to determine whether it can safely use a certain structure (e.g., bridges or tunnels), based on the vehicle size and the information on the structure geometry (received from the infrastructure). If necessary, the driver is warned, enabling rerouting the vehicle and avoiding a collision.

Overtaking Vehicle Warning

When vehicle A (red in the picture) is about to overtake, it sends a warning signal to vehicle B (white in the picture) via V2V-communication. Having received the warning, the vehicle B driver knows that there is a vehicle planning to pull out into the lane of vehicle B towards it and thus can react accordingly (including that vehicle B sends a warning signal to vehicle A).


A platoon is a group of vehicles that travel together as a coordinated sequence.

V2V-communication between the members of a platoon allows, for example, automatic maintaining of the gap between them, synchronized longitudinal and lateral maneuvers, and safe “connected braking”. The platoon vehicles also exchange speed and sensor data. Other connected vehicles can communicate their intention to turn off to the platoon so that the platoon vehicles perform coordinated decoupling and let the former turn.

Railroad Crossing Violation Warning

When a connected vehicle approaches a level (railway) crossing, it receives information about the intersection and presence of trains. If there is a risk of collision with a crossing or approaching train, the driver will receive Railroad Crossing Violation Warning. The application can also communicate the estimated amount of time the train needs to pass the intersection.

Red Light Violation Warning

A connected vehicle approaching a traffic light (white car in the picture) receives information from the infrastructure. The Red Light Violation application uses the received information about traffic signal timing and intersection geometry, and the vehicle’s own speed/acceleration profile; and provides a warning if the vehicle appears to violate the traffic signal entering the intersection. Additionally, the warnings about potential violations can be sent to other vehicles at the intersection via V2V-communication (blue and red cars in the picture).

Reduced Speed Zone Warning / Lane Closure

The application provides connected vehicles with information on the speed limit and/or roadway configuration changes (e.g., lane closures/shifts) in an upcoming reduced speed zone (e.g., school zones, construction/work zones, pedestrian crossing areas) via V2I-communication. The in-vehicle application uses this infrastructure information and vehicle-based data to generate appropriate notifications to the driver in time.

Restricted Lane Warning

With the help of this application, a connected vehicle receives the information on travel lane restrictions (e.g., to high occupancy vehicles or with an eco-criteria) and can determine if it is in a “correct” lane.

Roadside Alert, Warnings about upcoming Workzone/Hazards in a Work Zone

When a connected car approaches the corresponding zone, the driver receives an alert message, which includes such information as travel delays, diversion data, maintenance/construction work. The latter is also known as Warnings about Upcoming Work Zone, providing extended information about work zone activities that can create unsafe conditions for the approaching vehicle: obstructions in the vehicle travel lane, lane closures or shifts, vehicles entering/exiting the work zone. Maintenance personnel can be also alerted about unsafe conditions (e.g., a vehicle moving at high speed or entering the work zone) via Warnings about Hazards in a Work Zone application.

Slow/Stationary Vehicle Warning

The driver of a connected vehicle, approaching a slow or a stationary vehicle (e.g. emergency or road maintenance vehicle), receives a warning message in advance so that the driver can act accordingly. Warning signals can be sent via V2V-communication when the vehicles are equipped with the necessary technology or initialised by traffic management centers.

Smart Parking [Traveler Information System]

Smart Parking application delivers information regarding parking lot location, type, space availability, and pricing. In general, Traveler Information System provides two types of message exchange in the framework of connected driving: one-way predefined information broadcast to travelers (transportation system users) and two-way communication, whereby the traveler makes personalised requests and receives specific information. Messages examples include traffic information, traffic incidents, evacuations, weather, and public transport schedules.

Stop Sign Gap Assist

The application helps the driver of a connected vehicle waiting at the STOP-sign (minor road) to understand the situation on the major road and warns the driver about unsafe gaps to enter the intersection.

Stop Sign Violation WarningStop Sign Violation Warning

Based on the vehicle’s speed and distance to the intersection (information about the intersection geometry is received from the infrastructure), the application warns the driver about the potential violation of an upcoming stop sign (at an unsignalized intersection).

Tailgating Advisory

The application collects the information from other vehicles and verifies if vehicle A is driving at a safe distance from vehicle B in front of it. The application warns the driver of the vehicle A if she is driving too close to vehicle B.

Time-to-Green & GLOSA (Green Light Optimal Speed Advisory)

Via Time-to-Green application a connected vehicle that is approaching a red traffic light receives information from the infrastructure when the traffic light will change to green/how much longer it will remain red. Via GLOSA the information is extended to speed advice: at which speed the vehicle should approach the intersection so that the lights turn green by the time the vehicle is ready to cross the intersection. Connected vehicles can also receive such information as how long the traffic light will remain green and approaching at which speed the vehicle is able to cross the intersection on time.

Traffic Signal Priority Request/Preemption

The infrastructure receives the information of an emergency vehicle and enables to set up a green wave for it. Additionally, this application can facilitate clearing traffic congestions. Traffic Signal Priority Requests can be also carried out with respect to other High Priority Vehicles (e.g., public transport or HGV).

Transit Vehicle at Station/Stop Warnings

If there is a bus at a bus stop, an alert will be sent to connected vehicles in the relevant proximity. The application also communicates the information about the following pulling in or out of the bus.

(Right/Left) Turn Assist

When traffic at an intersection is not precisely regulated by traffic lights, turning can present certain difficulties. Thus, it is easy to overlook oncoming traffic or to estimate the speed incorrectly. Besides that, the sight of the intersection can be obstructed. With the help of Turn Assist applications, connected vehicles timely exchange information about their intentions via V2V-communication so that the drivers can act accordingly (brake, give priority, etc.). Via V2I-communication connected vehicles notify the infrastructure about their intentions so that additional warnings could be issued (e.g., flashing yellow light).

Vehicle Turning Right in Front of a Transit Vehicle

The driver of a bus that is about to leave a bus stop receives a warning if there a vehicle overtaking the bus to make a right turn in front of it – and can act accordingly.

VRU Protection

Vulnerable Road Users (VRUs) are defined as “non-motorised road users, such as pedestrians and cyclists as well as motorcyclists and persons with disabilities or reduced mobility and orientation” © ITS Directive

The communication between connected vehicles and VRUs can be either direct or infrastructure-assisted.

Pedestrian Crossing Warning, Transit Bus Stop Pedestrian Warning

The presence of pedestrians can be detected with the help of infrastructure, for example via sensors or using the information of pedestrian button activation at an intersection. The infrastructure then sends alerts to connected vehicles in proximity. The application could also warn the pedestrians of a vehicle at the intersection or violating the crosswalk boundaries. Pedestrians at bus stops are alerted about transit vehicles’ presence and movements (and connected vehicles nearby of pedestrians in danger of collision).

In a V2V-communication based scenario, a connected vehicle (red in the picture) at the intersection perceives pedestrians via sensors (e.g., camera, LIDAR) and sends the information to connected vehicles in proximity (white in the picture) so that they can act accordingly. Such messages compensate for the limitations of sensors (e.g., due to intersection geometry).

Pedestrians can also have an application (usually on a smartphone) that would allow them to exchange safety messages (containing location, speed, and direction information) with connected vehicles and send warnings when a collision is predicted.

Pedestrian detection warning © Andreas Schlichter
Bicycle/Motorcycle Approaching Information & Warning

Bicycles and motorcycles are often overseen by car drivers due to their size, especially when a driver is distracted or in low-visibility conditions. In a connected driving scenario, the vehicle is informed of the bicycle’s or motorcycle’s presence in real-time with the help of the signals received from the VRUs (e.g. via smartphone). The vehicle can also predict the collision probability and warn the driver.

Wrong-Way Driver Detection & Warning

A vehicle going in the wrong direction is detected via sensors (cameras, radars, etc.) or if the information about vehicle movement (communicated by the vehicle itself) does not align with the permitted direction of travel. ITS infrastructure sends a warning signal to both the wrong-way driver and the connected vehicles in the danger area. The warning can be also displayed via traditional infrastructure, such as an illuminated “WRONG WAY” sign (on the way of the wrong-way driver) and geofenced alerts of incoming danger on overhead boards.

Warning of driving in the wrong direction © Andreas Schlichter
Warning of a wrong-way driver © Andreas Schlichter