Traffic Events

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The Maps SDK for Flutter provides real-time information about traffic events, such as delays, which can occur in various forms.

When enabled and supported by the applied map style, traffic events are visually represented on the map as red overlays on affected road segments.

Based on the source of the event:

• Most traffic events are provided by the Magic Lane servers if online and provide up-to-date traffic data
• The user can add custom user-defined roadblocks in order to blacklist certain road segments or areas.

Based on the impact zone:

• The traffic event can be a path-based traffic area, following the shape of a road.
• The traffic event can be an area-based traffic area, including a larger geographic area.

The central class for handling both traffic events and roadblocks is TrafficEvent. Instances of this class can be obtained either through user interaction with the map (e.g., selecting a road segment) or as part of user-defined roadblock operations. For route-specific traffic data, the SDK provides the RouteTrafficEvent class, which extends TrafficEvent by including detailed information relevant to a specific route. These events are provided by the route.

Traffic events, including delays and user-defined roadblocks, are fully integrated into the routing and navigation logic. This ensures that calculated routes dynamically account for traffic conditions and any restricted segments.

TrafficEvent structure

The TrafficEvent class has the following structure:

Member	Type	Description
isRoadblock	bool	Returns true if the event represents a roadblock.
delay	int	Estimated delay in seconds. Returns -1 if unknown.
length	int	Length in meters of the road segment affected. Returns -1 if unknown if the event is an area-based roadblock.
impactZone	TrafficEventImpactZone	Indicates if the event affects a point or area.
referencePoint	Coordinates	The central coordinate for the event. Returns (0,0) for area events.
boundingBox	RectangleGeographicArea	Geographical bounding box surrounding the event.
description	String	Human-readable description of the traffic event. If it is a user-defined roadblock contains the id
eventClass	TrafficEventClass	Classification of the traffic event.
eventSeverity	TrafficEventSeverity	Severity level of the event.
getImage({size, format})	Uint8List?	Returns an image representing the traffic event.
img	Img	Retrieves the event image in internal format (Img).
previewUrl	String	Returns a URL to preview the traffic event. Returns emtpy if not available (user-defined roadblock).
isUserRoadblock	bool	Returns true if the event is a user-defined roadblock.
affectedTransportModes	Set<TrafficTransportMode>	Returns all transport modes affected by the event.
startTime	DateTime?	UTC start time of the traffic event, if available.
endTime	DateTime?	UTC end time of the traffic event, if available.
hasOppositeSibling	bool	Returns true if a sibling event exists in the opposite direction. Relevant for path-based events.

RouteTrafficEvent structure

The RouteTrafficEvent class extends TrafficEvent with the following members:

Member	Type	Description
distanceToDestination	int	Returns the distance in meters from the event's position on the route to the destination. Returns 0 if unavailable.
from	Coordinates	The starting point of the traffic event on the route.
to	Coordinates	The end point of the traffic event on the route.
fromLandmark	Pair<Landmark, bool>	Returns the starting point as a landmark and a flag indicating if data is cached locally.
toLandmark	Pair<Landmark, bool>	Returns the end point as a landmark and a flag indicating if data is cached locally.
asyncUpdateToFromData()	void Function(GemError)	Asynchronously updates the from and to landmarks' address and description info from the server.
cancelUpdate()	void	Cancels the pending async update request for landmark data.

Usage

• Used to provide traffic information about a route. See the Get ETA and Traffic information guide for more details.
• Used to implement user-defined roadblocks. See the Get ETA and Traffic information guide for more details.

Traffic events provide insights into road conditions, delays, closures, and more. Some events provided by the TrafficEventClass are:

• trafficRestrictions
• roadworks
• parking
• delays
• accidents
• roadConditions

TrafficEventSeverity possible values are: stationary, queuing, slowTraffic, possibleDelay, unknown.