diff --git a/docs/mock-locations-routes.md b/docs/mock-locations-routes.md
index a5787f8..ac6d6a5 100644
--- a/docs/mock-locations-routes.md
+++ b/docs/mock-locations-routes.md
@@ -1,8 +1,8 @@
-#Mock Locations
+# Mock Locations
 
 With Lost you can mock not just individual locations but also entire routes. By loading a [GPX trace file](http://www.topografix.com/gpx.asp) onto the device you can configure Lost to replay locations from the trace file including latitude, longitude, speed, and bearing.
 
-**Mocking a single location**
+## Mocking a single location
 To mock a single location with Lost you must first enable mock mode. Then you simply create a mock location object and pass it to the API.
 
 ```java
@@ -16,11 +16,28 @@ LocationServices.FusedLocationApi.setMockLocation(mockLocation);
 
 The mock location object you set will be immediately returned to all registered listeners and will be returned the next time `getLastLocation()` is called.
 
-**Mocking an entire route**
-To mock an entire route you must first transfer a [GPX trace file](http://www.topografix.com/gpx.asp) to the device using [adb](http://developer.android.com/tools/help/adb.html). Sample GPX traces can be found on the [public GPS traces page](http://www.openstreetmap.org/traces) for OpenStreetMap. Once the trace file is loaded on the device you can tell Lost to replay the locations in the trace at the requested update interval.
+## Mocking an entire route
+To mock an entire route you must first transfer a [GPX trace file](http://www.topografix.com/gpx.asp) to the device using [adb](http://developer.android.com/tools/help/adb.html). Sample GPX traces can be found on the [public GPS traces page](http://www.openstreetmap.org/traces) for OpenStreetMap.
+
+### Install GPX File
+To install your gpx file onto your device, run the `install-gpx-trace.sh` script provided.
+
+Example:
+
+```bash
+install-gpx-trace.sh lost.gpx com.example.myapp
+```
+
+Once the trace file is loaded on the device you can tell Lost to replay the locations in the trace by issuing a `LocationRequest`. Mock locations will be emitted according to the fastest interval value.
 
 ```java
-File file = new File(Environment.getExternalStorageDirectory(), "mock_track.gpx");
+File file = new File(context.getExternalFilesDir(null), "lost.gpx");
 LocationServices.FusedLocationApi.setMockMode(true);
 LocationServices.FusedLocationApi.setMockTrace(file);
+LocationRequest locationRequest = LocationRequest.create()
+    .setInterval(1000)
+    .setFastestInterval(1000) // Mock locations will replay at this interval.
+    .setSmallestDisplacement(0)
+    .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
+FusedLocationApi.requestLocationUpdates(lostApiClient, locationRequest, locationListener);
 ```
diff --git a/lost-sample/src/main/java/com/example/lost/LocationListenerActivity.java b/lost-sample/src/main/java/com/example/lost/LocationListenerActivity.java
index 48ab753..ddc0d14 100644
--- a/lost-sample/src/main/java/com/example/lost/LocationListenerActivity.java
+++ b/lost-sample/src/main/java/com/example/lost/LocationListenerActivity.java
@@ -150,22 +150,25 @@ private boolean isMockModePrefEnabled() {
 
     if (prefs.getBoolean(getString(R.string.mock_mode_gpx_key), false)) {
       String filename = prefs.getString(getString(R.string.mock_gpx_file_key), null);
-      File file = new File(Environment.getExternalStorageDirectory(), filename);
+      File file = new File(getExternalFilesDir(null), filename);
       FusedLocationApi.setMockTrace(client, file);
     }
 
+    final Resources res = getResources();
+
     final String intervalKey = getString(R.string.interval_key);
     final String displacementKey = getString(R.string.displacement_key);
     final String priorityKey = getString(R.string.priority_key);
 
-    final Resources res = getResources();
+    final int intervalDefaultValue = res.getInteger(R.integer.interval_default_value);
+    final int displacementDefaultValue = res.getInteger(R.integer.displacement_default_value);
+    final int priorityDefaultValue = res.getInteger(R.integer.priority_default_value);
+
     final LocationRequest locationRequest = LocationRequest.create()
-        .setInterval(
-            prefs.getInt(intervalKey, res.getInteger(R.integer.interval_default_value)))
-        .setSmallestDisplacement(
-            prefs.getInt(displacementKey, res.getInteger(R.integer.displacement_default_value)))
-        .setPriority(
-            prefs.getInt(priorityKey, res.getInteger(R.integer.priority_default_value)));
+        .setInterval(prefs.getInt(intervalKey, intervalDefaultValue))
+        .setFastestInterval(prefs.getInt(intervalKey, intervalDefaultValue))
+        .setSmallestDisplacement(prefs.getInt(displacementKey, displacementDefaultValue))
+        .setPriority(prefs.getInt(priorityKey, priorityDefaultValue));
 
     FusedLocationApi.requestLocationUpdates(client, locationRequest, listener);
 
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImpl.java b/lost/src/main/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImpl.java
index 0059e03..5811cf0 100644
--- a/lost/src/main/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImpl.java
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImpl.java
@@ -175,7 +175,7 @@ private void toggleMockMode() {
     mockMode = !mockMode;
     locationEngine.setRequest(null);
     if (mockMode) {
-      locationEngine = new MockEngine(context, this);
+      locationEngine = new MockEngine(context, this, new GpxTraceThreadFactory());
     } else {
       locationEngine = new FusionEngine(context, this);
     }
@@ -186,5 +186,4 @@ private void notifyLocationAvailabilityChanged() {
     final LocationAvailability availability = locationEngine.createLocationAvailability();
     clientManager.notifyLocationAvailability(availability);
   }
-
 }
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/GpxTraceThreadFactory.java b/lost/src/main/java/com/mapzen/android/lost/internal/GpxTraceThreadFactory.java
new file mode 100644
index 0000000..1f6edc2
--- /dev/null
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/GpxTraceThreadFactory.java
@@ -0,0 +1,12 @@
+package com.mapzen.android.lost.internal;
+
+import android.content.Context;
+
+import java.io.File;
+
+public class GpxTraceThreadFactory implements TraceThreadFactory {
+  @Override public TraceThread createTraceThread(Context context, File traceFile, MockEngine engine,
+      SleepFactory sleepFactory) {
+    return new TraceThread(context, traceFile, engine, sleepFactory);
+  }
+}
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/LocationRequestUnbundled.java b/lost/src/main/java/com/mapzen/android/lost/internal/LocationRequestUnbundled.java
index c1d0d65..57fa8af 100644
--- a/lost/src/main/java/com/mapzen/android/lost/internal/LocationRequestUnbundled.java
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/LocationRequestUnbundled.java
@@ -6,7 +6,7 @@
 import java.util.List;
 
 /**
- *
+ * Set of location requests used to synthesize parameters for location updates.
  */
 public class LocationRequestUnbundled {
 
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/MockEngine.java b/lost/src/main/java/com/mapzen/android/lost/internal/MockEngine.java
index f3b6dbf..4615785 100644
--- a/lost/src/main/java/com/mapzen/android/lost/internal/MockEngine.java
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/MockEngine.java
@@ -1,24 +1,9 @@
 package com.mapzen.android.lost.internal;
 
-import org.w3c.dom.Document;
-import org.w3c.dom.Node;
-import org.w3c.dom.NodeList;
-import org.xml.sax.SAXException;
-
 import android.content.Context;
 import android.location.Location;
-import android.os.Handler;
 
 import java.io.File;
-import java.io.IOException;
-
-import javax.xml.parsers.DocumentBuilder;
-import javax.xml.parsers.DocumentBuilderFactory;
-import javax.xml.parsers.ParserConfigurationException;
-import javax.xml.xpath.XPath;
-import javax.xml.xpath.XPathConstants;
-import javax.xml.xpath.XPathExpressionException;
-import javax.xml.xpath.XPathFactory;
 
 /**
  * Mock implementation of LocationEngine that reports single locations and/or full GPX traces.
@@ -26,18 +11,15 @@
 public class MockEngine extends LocationEngine {
   public static final String MOCK_PROVIDER = "mock";
 
-  // GPX tags
-  public static final String TAG_TRACK_POINT = "trkpt";
-  public static final String TAG_SPEED = "speed";
-  public static final String TAG_LAT = "lat";
-  public static final String TAG_LNG = "lon";
-
   private Location location;
   private File traceFile;
+  private TraceThreadFactory traceThreadFactory;
   protected TraceThread traceThread;
 
-  public MockEngine(Context context, FusionEngine.Callback callback) {
+  public MockEngine(Context context, FusionEngine.Callback callback,
+      TraceThreadFactory traceThreadFactory) {
     super(context, callback);
+    this.traceThreadFactory = traceThreadFactory;
   }
 
   @Override public Location getLastLocation() {
@@ -50,7 +32,8 @@ public MockEngine(Context context, FusionEngine.Callback callback) {
 
   @Override protected void enable() {
     if (traceFile != null) {
-      traceThread = new TraceThread();
+      traceThread = traceThreadFactory.createTraceThread(getContext(), traceFile, this,
+          new ThreadSleepFactory());
       traceThread.start();
     }
   }
@@ -82,91 +65,4 @@ public void setTrace(File file) {
   public File getTrace() {
     return traceFile;
   }
-
-  protected class TraceThread extends Thread {
-    private boolean canceled;
-    private Location previous;
-
-    public void cancel() {
-      canceled = true;
-      interrupt();
-    }
-
-    @Override public void run() {
-      final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
-      final XPath xPath = XPathFactory.newInstance().newXPath();
-      final String expression = "//" + TAG_TRACK_POINT;
-      final String speedExpression = "//" + TAG_SPEED;
-
-      NodeList nodeList = null;
-      NodeList speedList = null;
-      try {
-        DocumentBuilder builder = factory.newDocumentBuilder();
-        Document document = builder.parse(traceFile);
-        nodeList = (NodeList) xPath.compile(expression).evaluate(document, XPathConstants.NODESET);
-        speedList =
-            (NodeList) xPath.compile(speedExpression).evaluate(document, XPathConstants.NODESET);
-      } catch (ParserConfigurationException e) {
-        e.printStackTrace();
-      } catch (SAXException e) {
-        e.printStackTrace();
-      } catch (IOException e) {
-        e.printStackTrace();
-      } catch (XPathExpressionException e) {
-        e.printStackTrace();
-      }
-
-      parse(nodeList, speedList);
-    }
-
-    private void parse(NodeList nodeList, NodeList speedList) {
-      if (nodeList != null) {
-        for (int i = 0; i < nodeList.getLength(); i++) {
-          postMockLocation(nodeToLocation(nodeList, speedList, i));
-          sleepFastestInterval();
-        }
-      }
-    }
-
-    private Location nodeToLocation(NodeList nodeList, NodeList speedList, int i) {
-      final Node node = nodeList.item(i);
-      String lat = node.getAttributes().getNamedItem(TAG_LAT).getNodeValue();
-      String lng = node.getAttributes().getNamedItem(TAG_LNG).getNodeValue();
-
-      final Location location = new Location(MOCK_PROVIDER);
-      location.setLatitude(Double.parseDouble(lat));
-      location.setLongitude(Double.parseDouble(lng));
-      location.setTime(System.currentTimeMillis());
-      if (speedList.item(i) != null && speedList.item(i).getFirstChild() != null) {
-        location.setSpeed(Float.parseFloat(speedList.item(i).getFirstChild().getNodeValue()));
-      }
-
-      if (previous != null) {
-        location.setBearing(previous.bearingTo(location));
-      }
-
-      previous = location;
-      return location;
-    }
-
-    private void sleepFastestInterval() {
-      if (getRequest() != null) {
-        try {
-          Thread.sleep(getRequest().getFastestInterval());
-        } catch (InterruptedException e) {
-          canceled = true;
-        }
-      }
-    }
-
-    private void postMockLocation(final Location mockLocation) {
-      new Handler(getContext().getMainLooper()).post(new Runnable() {
-        @Override public void run() {
-          if (!canceled) {
-            setLocation(mockLocation);
-          }
-        }
-      });
-    }
-  }
 }
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/SleepFactory.java b/lost/src/main/java/com/mapzen/android/lost/internal/SleepFactory.java
new file mode 100644
index 0000000..eae28b7
--- /dev/null
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/SleepFactory.java
@@ -0,0 +1,5 @@
+package com.mapzen.android.lost.internal;
+
+interface SleepFactory {
+  void sleep(long millis);
+}
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/ThreadSleepFactory.java b/lost/src/main/java/com/mapzen/android/lost/internal/ThreadSleepFactory.java
new file mode 100644
index 0000000..52697e6
--- /dev/null
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/ThreadSleepFactory.java
@@ -0,0 +1,11 @@
+package com.mapzen.android.lost.internal;
+
+class ThreadSleepFactory implements SleepFactory {
+  @Override public void sleep(long millis) {
+    try {
+      Thread.sleep(millis);
+    } catch (InterruptedException e) {
+      e.printStackTrace();
+    }
+  }
+}
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/TraceThread.java b/lost/src/main/java/com/mapzen/android/lost/internal/TraceThread.java
new file mode 100644
index 0000000..4b72eb5
--- /dev/null
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/TraceThread.java
@@ -0,0 +1,127 @@
+package com.mapzen.android.lost.internal;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+import org.xml.sax.SAXException;
+
+import android.content.Context;
+import android.location.Location;
+import android.os.Handler;
+
+import java.io.File;
+import java.io.IOException;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+
+class TraceThread extends Thread {
+  // GPX tags
+  private static final String TAG_TRACK_POINT = "trkpt";
+  private static final String TAG_SPEED = "speed";
+  private static final String TAG_LAT = "lat";
+  private static final String TAG_LNG = "lon";
+
+  private boolean canceled;
+  private Location previous;
+
+  private final Context context;
+  private final File traceFile;
+  private final MockEngine engine;
+  private final SleepFactory sleepFactory;
+
+  TraceThread(Context context, File traceFile, MockEngine engine, SleepFactory sleepFactory) {
+    this.context = context;
+    this.traceFile = traceFile;
+    this.engine = engine;
+    this.sleepFactory = sleepFactory;
+  }
+
+  public void cancel() {
+    canceled = true;
+    interrupt();
+  }
+
+  public boolean isCanceled() {
+    return canceled;
+  }
+
+  @Override public void run() {
+    final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+    final XPath xPath = XPathFactory.newInstance().newXPath();
+    final String expression = "//" + TAG_TRACK_POINT;
+    final String speedExpression = "//" + TAG_SPEED;
+
+    NodeList nodeList = null;
+    NodeList speedList = null;
+    try {
+      DocumentBuilder builder = factory.newDocumentBuilder();
+      Document document = builder.parse(traceFile);
+      nodeList = (NodeList) xPath.compile(expression).evaluate(document, XPathConstants.NODESET);
+      speedList =
+          (NodeList) xPath.compile(speedExpression).evaluate(document, XPathConstants.NODESET);
+    } catch (ParserConfigurationException e) {
+      e.printStackTrace();
+    } catch (SAXException e) {
+      e.printStackTrace();
+    } catch (IOException e) {
+      e.printStackTrace();
+    } catch (XPathExpressionException e) {
+      e.printStackTrace();
+    }
+
+    parse(nodeList, speedList);
+  }
+
+  private void parse(NodeList nodeList, NodeList speedList) {
+    if (nodeList != null) {
+      for (int i = 0; i < nodeList.getLength(); i++) {
+        postMockLocation(nodeToLocation(nodeList, speedList, i));
+        sleepFastestInterval();
+      }
+    }
+  }
+
+  private Location nodeToLocation(NodeList nodeList, NodeList speedList, int i) {
+    final Node node = nodeList.item(i);
+    String lat = node.getAttributes().getNamedItem(TAG_LAT).getNodeValue();
+    String lng = node.getAttributes().getNamedItem(TAG_LNG).getNodeValue();
+
+    final Location location = new Location(MockEngine.MOCK_PROVIDER);
+    location.setLatitude(Double.parseDouble(lat));
+    location.setLongitude(Double.parseDouble(lng));
+    location.setTime(System.currentTimeMillis());
+    if (speedList.item(i) != null && speedList.item(i).getFirstChild() != null) {
+      location.setSpeed(Float.parseFloat(speedList.item(i).getFirstChild().getNodeValue()));
+    }
+
+    if (previous != null) {
+      location.setBearing(previous.bearingTo(location));
+    }
+
+    previous = location;
+    return location;
+  }
+
+  private void sleepFastestInterval() {
+    final LocationRequestUnbundled request = engine.getRequest();
+    if (request != null) {
+      sleepFactory.sleep(request.getFastestInterval());
+    }
+  }
+
+  private void postMockLocation(final Location mockLocation) {
+    new Handler(context.getMainLooper()).post(new Runnable() {
+      @Override public void run() {
+        if (!canceled) {
+          engine.setLocation(mockLocation);
+        }
+      }
+    });
+  }
+}
diff --git a/lost/src/main/java/com/mapzen/android/lost/internal/TraceThreadFactory.java b/lost/src/main/java/com/mapzen/android/lost/internal/TraceThreadFactory.java
new file mode 100644
index 0000000..085fdbf
--- /dev/null
+++ b/lost/src/main/java/com/mapzen/android/lost/internal/TraceThreadFactory.java
@@ -0,0 +1,10 @@
+package com.mapzen.android.lost.internal;
+
+import android.content.Context;
+
+import java.io.File;
+
+public interface TraceThreadFactory {
+  TraceThread createTraceThread(Context context, File traceFile, MockEngine engine,
+      SleepFactory sleepFactory);
+}
diff --git a/lost/src/test/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImplTest.java b/lost/src/test/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImplTest.java
index 1590835..f7c4210 100644
--- a/lost/src/test/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImplTest.java
+++ b/lost/src/test/java/com/mapzen/android/lost/internal/FusedLocationProviderServiceImplTest.java
@@ -15,7 +15,6 @@
 
 import org.junit.After;
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.robolectric.RobolectricGradleTestRunner;
@@ -323,7 +322,6 @@ private void mockService() {
     assertThat(listener.getMostRecentLocation()).isEqualTo(mockLocation);
   }
 
-  @Test @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
   public void setMockTrace_shouldInvokeListenerForEachLocation() throws Exception {
     api.setMockMode(client, true);
     api.setMockTrace(client, getTestGpxTrace());
@@ -342,7 +340,6 @@ public void setMockTrace_shouldInvokeListenerForEachLocation() throws Exception
     assertThat(listener.getAllLocations().get(2).getLongitude()).isEqualTo(2.1);
   }
 
-  @Test @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
   public void setMockTrace_shouldBroadcastSpeedWithLocation() throws Exception {
     api.setMockMode(client, true);
     api.setMockTrace(client, getTestGpxTrace());
@@ -357,7 +354,6 @@ public void setMockTrace_shouldBroadcastSpeedWithLocation() throws Exception {
     assertThat(listener.getAllLocations().get(2).getSpeed()).isEqualTo(30f);
   }
 
-  @Test @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
   public void setMockTrace_shouldRespectFastestInterval() throws Exception {
     api.setMockMode(client, true);
     api.setMockTrace(client, getTestGpxTrace());
diff --git a/lost/src/test/java/com/mapzen/android/lost/internal/MockEngineTest.java b/lost/src/test/java/com/mapzen/android/lost/internal/MockEngineTest.java
index 3849cbb..28319cb 100644
--- a/lost/src/test/java/com/mapzen/android/lost/internal/MockEngineTest.java
+++ b/lost/src/test/java/com/mapzen/android/lost/internal/MockEngineTest.java
@@ -7,34 +7,34 @@
 import com.google.common.io.Files;
 
 import org.junit.Before;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.robolectric.RobolectricGradleTestRunner;
+import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
 import org.robolectric.shadows.ShadowEnvironment;
-import org.robolectric.shadows.ShadowLooper;
 
+import android.content.Context;
 import android.location.Location;
 import android.os.Environment;
 
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
-import java.util.ArrayList;
 
 import static org.fest.assertions.api.Assertions.assertThat;
 import static org.robolectric.RuntimeEnvironment.application;
 
-@RunWith(RobolectricGradleTestRunner.class)
+@RunWith(RobolectricTestRunner.class)
 @Config(constants = BuildConfig.class, sdk = 21, manifest = Config.NONE)
 public class MockEngineTest {
   private MockEngine mockEngine;
   private TestCallback callback;
+  private TestTraceThreadFactory traceThreadFactory;
 
   @Before public void setUp() throws Exception {
     callback = new TestCallback();
-    mockEngine = new MockEngine(application, callback);
+    traceThreadFactory = new TestTraceThreadFactory();
+    mockEngine = new MockEngine(application, callback, traceThreadFactory);
   }
 
   @Test public void shouldNotBeNull() throws Exception {
@@ -47,97 +47,11 @@ public class MockEngineTest {
     assertThat(callback.lastLocation).isEqualTo(mockLocation);
   }
 
-  @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
-  @Test public void setTrace_shouldReportEachLocation() throws Exception {
-    mockEngine.setTrace(getTestGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(0));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations).hasSize(3);
-    assertThat(callback.locations.get(0).getLatitude()).isEqualTo(0.0);
-    assertThat(callback.locations.get(0).getLongitude()).isEqualTo(0.1);
-    assertThat(callback.locations.get(1).getLatitude()).isEqualTo(1.0);
-    assertThat(callback.locations.get(1).getLongitude()).isEqualTo(1.1);
-    assertThat(callback.locations.get(2).getLatitude()).isEqualTo(2.0);
-    assertThat(callback.locations.get(2).getLongitude()).isEqualTo(2.1);
-  }
-
-  @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
-  @Test public void setTrace_shouldReportSpeed() throws Exception {
-    mockEngine.setTrace(getTestGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(0));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations.get(0).getSpeed()).isEqualTo(10f);
-    assertThat(callback.locations.get(1).getSpeed()).isEqualTo(20f);
-    assertThat(callback.locations.get(2).getSpeed()).isEqualTo(30f);
-  }
-
-  @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
-  @Test public void setTrace_shouldCalculateBearing() throws Exception {
-    mockEngine.setTrace(getTestGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(0));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations.get(0).getBearing()).isEqualTo(0.0f);
-    assertThat(callback.locations.get(1).getBearing()).isEqualTo(
-        callback.locations.get(0).bearingTo(callback.locations.get(1)));
-    assertThat(callback.locations.get(2).getBearing()).isEqualTo(
-        callback.locations.get(1).bearingTo(callback.locations.get(2)));
-  }
-
-  @Test public void setTrace_shouldSetHasBearing() throws Exception {
-    mockEngine.setTrace(getTestGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(0));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations.get(0).hasBearing()).isFalse();
-    assertThat(callback.locations.get(1).hasBearing()).isTrue();
-    assertThat(callback.locations.get(2).hasBearing()).isTrue();
-  }
-
-  @Test public void setTrace_shouldRespectFastestInterval() throws Exception {
+  @Test public void disable_shouldCancelTraceReplay() throws Exception {
     mockEngine.setTrace(getTestGpxTrace());
     mockEngine.setRequest(LocationRequest.create().setFastestInterval(100));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations).hasSize(1);
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations).hasSize(2);
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations).hasSize(3);
-  }
-
-  @Test @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
-  public void setTrace_shouldNotRequireSpeed() throws Exception {
-    mockEngine.setTrace(getTestGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(0));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations.get(0).hasSpeed()).isTrue();
-    mockEngine.disable();
-    callback.reset();
-    Thread.sleep(100);
-    mockEngine.setTrace(getNoSpeedGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(0));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations.get(0).hasSpeed()).isFalse();
-  }
-
-  @Test @Ignore("Intermittently failing. Find a better way to test without Thread.sleep(100)")
-  public void disable_shouldCancelTraceReplay() throws Exception {
-    mockEngine.setTrace(getTestGpxTrace());
-    mockEngine.setRequest(LocationRequest.create().setFastestInterval(100));
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations).hasSize(1);
     mockEngine.disable();
-    Thread.sleep(100);
-    ShadowLooper.runUiThreadTasks();
-    assertThat(callback.locations).hasSize(1);
+    assertThat(traceThreadFactory.traceThread.isCanceled()).isTrue();
   }
 
   public static File getGpxFile(String filename) throws IOException {
@@ -161,11 +75,9 @@ public static File getNoSpeedGpxTrace() throws IOException {
 
   class TestCallback implements LocationEngine.Callback {
     private Location lastLocation;
-    private ArrayList<Location> locations = new ArrayList<>();
 
     @Override public void reportLocation(Location location) {
       lastLocation = location;
-      locations.add(location);
     }
 
     @Override public void reportProviderDisabled(String provider) {
@@ -173,10 +85,21 @@ class TestCallback implements LocationEngine.Callback {
 
     @Override public void reportProviderEnabled(String provider) {
     }
+  }
+
+  static class TestTraceThreadFactory implements TraceThreadFactory {
+    private TestTraceThread traceThread;
+
+    @Override public TraceThread createTraceThread(Context context, File traceFile,
+        MockEngine engine, SleepFactory sleepFactory) {
+      traceThread = new TestTraceThread(context, traceFile, engine, sleepFactory);
+      return traceThread;
+    }
+  }
 
-    public void reset() {
-      lastLocation = null;
-      locations.clear();
+  static class TestTraceThread extends TraceThread {
+    TestTraceThread(Context context, File traceFile, MockEngine engine, SleepFactory sleepFactory) {
+      super(context, traceFile, engine, sleepFactory);
     }
   }
 }
diff --git a/lost/src/test/java/com/mapzen/android/lost/internal/TraceThreadTest.java b/lost/src/test/java/com/mapzen/android/lost/internal/TraceThreadTest.java
new file mode 100644
index 0000000..d2e49c4
--- /dev/null
+++ b/lost/src/test/java/com/mapzen/android/lost/internal/TraceThreadTest.java
@@ -0,0 +1,158 @@
+package com.mapzen.android.lost.internal;
+
+import com.google.common.base.Charsets;
+import com.google.common.io.Files;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.shadows.ShadowEnvironment;
+
+import android.location.Location;
+import android.os.Environment;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.ArrayList;
+
+import static org.fest.assertions.api.Assertions.assertThat;
+import static org.robolectric.RuntimeEnvironment.application;
+
+@RunWith(RobolectricTestRunner.class) public class TraceThreadTest {
+  private TestMockEngine mockEngine;
+  private TestSleepFactory sleepFactory;
+  private TraceThread traceThread;
+
+  @Before public void setUp() throws Exception {
+    mockEngine = new TestMockEngine();
+    sleepFactory = new TestSleepFactory();
+    traceThread = new TraceThread(application, getTestGpxTrace(), mockEngine, sleepFactory);
+  }
+
+  @Test public void shouldNotBeNull() throws Exception {
+    assertThat(traceThread).isNotNull();
+  }
+
+  @Test public void shouldReportEachLocation() throws Exception {
+    traceThread.run();
+    assertThat(mockEngine.locations).hasSize(3);
+    assertThat(mockEngine.locations.get(0).getLatitude()).isEqualTo(0.0);
+    assertThat(mockEngine.locations.get(0).getLongitude()).isEqualTo(0.1);
+    assertThat(mockEngine.locations.get(1).getLatitude()).isEqualTo(1.0);
+    assertThat(mockEngine.locations.get(1).getLongitude()).isEqualTo(1.1);
+    assertThat(mockEngine.locations.get(2).getLatitude()).isEqualTo(2.0);
+    assertThat(mockEngine.locations.get(2).getLongitude()).isEqualTo(2.1);
+  }
+
+  @Test public void shouldReportSpeed() throws Exception {
+    traceThread.run();
+    assertThat(mockEngine.locations.get(0).getSpeed()).isEqualTo(10f);
+    assertThat(mockEngine.locations.get(1).getSpeed()).isEqualTo(20f);
+    assertThat(mockEngine.locations.get(2).getSpeed()).isEqualTo(30f);
+  }
+
+  @Test public void shouldCalculateBearing() throws Exception {
+    traceThread.run();
+    assertThat(mockEngine.locations.get(0).getBearing()).isEqualTo(0.0f);
+    assertThat(mockEngine.locations.get(1).getBearing())
+        .isEqualTo(mockEngine.locations.get(0).bearingTo(mockEngine.locations.get(1)));
+    assertThat(mockEngine.locations.get(2).getBearing())
+        .isEqualTo(mockEngine.locations.get(1).bearingTo(mockEngine.locations.get(2)));
+  }
+
+  @Test public void shouldSetHasBearing() throws Exception {
+    traceThread.run();
+    assertThat(mockEngine.locations.get(0).hasBearing()).isFalse();
+    assertThat(mockEngine.locations.get(1).hasBearing()).isTrue();
+    assertThat(mockEngine.locations.get(2).hasBearing()).isTrue();
+  }
+
+  @Test public void shouldRespectFastestInterval() throws Exception {
+    mockEngine.setRequest(new TestLocationRequestUnbundled(100));
+    traceThread.run();
+    assertThat(sleepFactory.sleepTimeInMillis).isEqualTo(300);
+  }
+
+  @Test public void shouldReportSpeedIfAvailable() throws Exception {
+    traceThread = new TraceThread(application, getTestGpxTrace(), mockEngine, sleepFactory);
+    traceThread.run();
+    assertThat(mockEngine.locations.get(0).hasSpeed()).isTrue();
+  }
+
+  @Test public void shouldNotReportSpeedIfNotAvailable() throws Exception {
+    traceThread = new TraceThread(application, getNoSpeedGpxTrace(), mockEngine, sleepFactory);
+    traceThread.run();
+    assertThat(mockEngine.locations.get(0).hasSpeed()).isFalse();
+  }
+
+  public static File getTestGpxTrace() throws IOException {
+    return getGpxFile("lost.gpx");
+  }
+
+  public static File getNoSpeedGpxTrace() throws IOException {
+    return getGpxFile("lost-no-speed.gpx");
+  }
+
+  public static File getGpxFile(String filename) throws IOException {
+    String contents = Files.toString(new File("src/test/resources/" + filename), Charsets.UTF_8);
+    ShadowEnvironment.setExternalStorageState(Environment.MEDIA_MOUNTED);
+    File directory = Environment.getExternalStorageDirectory();
+    File file = new File(directory, filename);
+    FileWriter fileWriter = new FileWriter(file, false);
+    fileWriter.write(contents);
+    fileWriter.close();
+    return file;
+  }
+
+  class TestMockEngine extends MockEngine {
+    private ArrayList<Location> locations = new ArrayList<>();
+    private LocationRequestUnbundled request = new TestLocationRequestUnbundled(0);
+
+    public TestMockEngine() {
+      super(application, new FusionEngine.Callback() {
+        @Override public void reportLocation(Location location) {
+        }
+
+        @Override public void reportProviderDisabled(String provider) {
+        }
+
+        @Override public void reportProviderEnabled(String provider) {
+        }
+      }, new MockEngineTest.TestTraceThreadFactory());
+    }
+
+    @Override public void setLocation(Location location) {
+      this.locations.add(location);
+    }
+
+    @Override protected LocationRequestUnbundled getRequest() {
+      return request;
+    }
+
+    public void setRequest(LocationRequestUnbundled request) {
+      this.request = request;
+    }
+  }
+
+  class TestLocationRequestUnbundled extends LocationRequestUnbundled {
+    private long fastestInterval;
+
+    TestLocationRequestUnbundled(long fastestInterval) {
+      this.fastestInterval = fastestInterval;
+    }
+
+    @Override public long getFastestInterval() {
+      return fastestInterval;
+    }
+  }
+
+  class TestSleepFactory implements SleepFactory {
+    private long sleepTimeInMillis;
+
+    @Override public void sleep(long millis) {
+      sleepTimeInMillis += millis;
+    }
+  }
+}
diff --git a/scripts/install-gpx-trace.sh b/scripts/install-gpx-trace.sh
new file mode 100755
index 0000000..42b999a
--- /dev/null
+++ b/scripts/install-gpx-trace.sh
@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This script installs a GPX trace file onto an emulator or device. The specified trace file is
+# copied to the app's external files directory (determined by the provided package name).
+#
+# Usage:
+#   install-gpx-trace.sh <trace file> <package name>
+#
+# Example:
+#   install-gpx-trace.sh lost.gpx com.example.myapp
+
+if [[ $# -eq 0 ]]; then
+    echo "Usage: ${0} <trace-file> <package-name>"
+    exit 1
+fi
+
+TRACE_FILE=$1
+
+if [[ -z "$2" ]]; then
+    PACKAGE_NAME="com.example.lost"
+else
+    PACKAGE_NAME=$2
+fi
+
+adb push "$1" /sdcard/Android/data/"$PACKAGE_NAME"/files/