Define Persistent Roadblock

_{Last updated: June 19, 2026 | 3 minutes read}

This example demonstrates how to define a persistent roadblock on a road by tapping the map, and how to center the camera on it. Once the map is loaded, the user should zoom in and tap a road; the tapped section is blocked for one minute and marked with red roadblock polylines (on one or both sides of the road, depending on the road type). Tapping a different road section moves the roadblock there. The map is fully 3D and interactive, supporting pan, pinch-zoom, rotate and tilt.

Zoom in and tap a road to define a roadblock

The map centers on the user-defined roadblock

Tracking the Current Roadblock

A single nullable field holds the roadblock currently placed by the user, so it can be removed before a new one is added.

MainActivity.ktView on Github

// The currently active roadblock; kept so it can be removed before placing a new one.
private var roadblock: TrafficEvent? = null

Handling Map Taps

Once the default map view is created, an onTouch handler is installed. Each tap sets cursorScreenPosition so the map can be hit-tested at that point. If the tap lands on an existing roadblock (cursorSelectionTrafficEvents with isRoadblock), it is ignored; otherwise, if it lands on a street (cursorSelectionStreets), the first street's coordinates are used to place a new roadblock.

MainActivity.ktView on Github

mapView.onTouch = { xy ->
    SdkCall.execute {
        // Tell the map view where the touch happened so hit-testing is accurate.
        gemSurfaceView.mapView?.cursorScreenPosition = xy

        // Ignore taps on existing roadblocks; only bare street taps place new ones.
        val trafficEvents = gemSurfaceView.mapView?.cursorSelectionTrafficEvents
        if (!trafficEvents.isNullOrEmpty() && trafficEvents[0].isRoadblock) {
            return@execute
        }

        val streets = gemSurfaceView.mapView?.cursorSelectionStreets
        if (!streets.isNullOrEmpty()) {
            streets[0].coordinates?.let { addPersistentRoadblock(it) }
        }
    }
}

Adding the Roadblock

addPersistentRoadblock defines a roadblock that starts now and expires one minute later. If a previous roadblock exists, it is removed first via its reference point, then the new one is added with Traffic.addPersistentRoadblock for the car transport mode. When the resulting roadblock has a valid reference point, the camera is animated to its bounding box with centerOnRectArea - framed inside the free space left by the toolbar and system bars - and the on-screen hint is hidden.

MainActivity.ktView on Github

private fun addPersistentRoadblock(coordinates: Coordinates) {
    val startTime = Time.getUniversalTime()
    // The roadblock expires after 1 minute; incrementing the minute field is how the SDK API works.
    val endTime = Time.getUniversalTime().also { it?.minute += 1 }

    if (startTime == null || endTime == null) return

    val traffic = Traffic()

    // Remove the previous roadblock before placing the new one at the tapped location.
    roadblock?.referencePoint?.let { traffic.removePersistentRoadblock(it) }

    roadblock = traffic.addPersistentRoadblock(
        coords = arrayListOf(coordinates),
        startUTC = startTime,
        expireUTC = endTime,
        transportMode = ERouteTransportMode.Car.value,
    )

    if (roadblock?.referencePoint?.valid() == true) {
        roadblock?.boundingBox?.let {
            gemSurfaceView.mapView?.centerOnRectArea(
                area = it,
                zoomLevel = -1,
                viewRc = getFreeSpaceRectangle(),
                animation = Animation(EAnimation.Linear, duration = 900),
            )
        }
        runOnAliveUi {
            binding.hint.visibility = View.GONE
            // Hint gone; restore the full-height viewport.
            updateFocusViewport()
        }
    }
}