Traffic Events

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The Maps SDK for Flutter provides real-time information about traffic events such as delays, roadworks, and accidents.

When enabled and supported by your map style, traffic events appear as red overlays on affected road segments.

Event sources:

• Magic Lane servers - Provide up-to-date traffic data when online
• User-defined roadblocks - Blacklist specific road segments or areas

Impact zones:

• Path-based - Follows the shape of a road
• Area-based - Covers a larger geographic area

The central class for handling traffic events and roadblocks is TrafficEvent. You can obtain instances through user interaction with the map or as part of roadblock operations. For route-specific traffic data, use the RouteTrafficEvent class, which extends TrafficEvent with detailed route information.

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 contains the following members:

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.
area	GeographicArea	The geographic area associated with the event (see TrafficService.addPersistentRoadblockByArea). If no area is provided, this is the same as boundingBox.
isAntiArea	bool	Check if the impact zone is the anti-area of the event area. Valid only for area impact zone.
isActive	bool	Check if traffic event is active ( i.e. is started ).
isExpired	bool	Check if traffic event is expired ( i.e. is ended ).
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.

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Understand RouteTrafficEvent structure

The RouteTrafficEvent class extends TrafficEvent with route-specific information:

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	(Landmark, bool)	Returns the starting point as a landmark and a flag indicating if data is cached locally.
toLandmark	(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.

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Use traffic events

Traffic events provide insights into road conditions, delays, and closures:

• Route traffic information - See the Get ETA and Traffic information guide
• User-defined roadblocks - See the Roadblocks guide

Event classifications

The TrafficEventClass provides the following event types:

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

Severity levels

The TrafficEventSeverity enum includes:

• stationary
• queuing
• slowTraffic
• possibleDelay
• unknown