# Traffic Events
Last updated:
October 18, 2026
\| 4 minutes read
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[](#trafficevent-structure "Direct link to 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` | 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. |
***
## Understand RouteTrafficEvent structure[](#understand-routetrafficevent-structure "Direct link to 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. |
***
## Use traffic events[](#use-traffic-events "Direct link to Use traffic events")
Traffic events provide insights into road conditions, delays, and closures:
* **Route traffic information** - See the [Get ETA and Traffic information guide](/docs/flutter/guides/routing/get-started-routing.md#retrieve-time-and-distance-information)
* **User-defined roadblocks** - See the [Roadblocks guide](/docs/flutter/guides/navigation/roadblocks.md)
### Event classifications[](#event-classifications "Direct link to Event classifications")
The `TrafficEventClass` provides the following event types:
* `trafficRestrictions`
* `roadworks`
* `parking`
* `delays`
* `accidents`
* `roadConditions`
### Severity levels[](#severity-levels "Direct link to Severity levels")
The `TrafficEventSeverity` enum includes:
* `stationary`
* `queuing`
* `slowTraffic`
* `possibleDelay`
* `unknown`