diff --git a/cartographer/mapping_2d/sparse_pose_graph.cc b/cartographer/mapping_2d/sparse_pose_graph.cc
index d719f3b..02f0c3f 100644
--- a/cartographer/mapping_2d/sparse_pose_graph.cc
+++ b/cartographer/mapping_2d/sparse_pose_graph.cc
@@ -48,7 +48,7 @@ SparsePoseGraph::SparsePoseGraph(
 SparsePoseGraph::~SparsePoseGraph() {
   WaitForAllComputations();
   common::MutexLocker locker(&mutex_);
-  CHECK(scan_queue_ == nullptr);
+  CHECK(work_queue_ == nullptr);
 }
 
 std::vector<mapping::SubmapId> SparsePoseGraph::GrowSubmapTransformsAsNeeded(
@@ -140,10 +140,10 @@ void SparsePoseGraph::AddScan(
 }
 
 void SparsePoseGraph::AddWorkItem(const std::function<void()>& work_item) {
-  if (scan_queue_ == nullptr) {
+  if (work_queue_ == nullptr) {
     work_item();
   } else {
-    scan_queue_->push_back(work_item);
+    work_queue_->push_back(work_item);
   }
 }
 
@@ -298,15 +298,15 @@ void SparsePoseGraph::ComputeConstraintsForScan(
       num_scans_since_last_loop_closure_ > options_.optimize_every_n_scans()) {
     CHECK(!run_loop_closure_);
     run_loop_closure_ = true;
-    // If there is a 'scan_queue_' already, some other thread will take care.
-    if (scan_queue_ == nullptr) {
-      scan_queue_ = common::make_unique<std::deque<std::function<void()>>>();
-      HandleScanQueue();
+    // If there is a 'work_queue_' already, some other thread will take care.
+    if (work_queue_ == nullptr) {
+      work_queue_ = common::make_unique<std::deque<std::function<void()>>>();
+      HandleWorkQueue();
     }
   }
 }
 
-void SparsePoseGraph::HandleScanQueue() {
+void SparsePoseGraph::HandleWorkQueue() {
   constraint_builder_.WhenDone(
       [this](const sparse_pose_graph::ConstraintBuilder::Result& result) {
         {
@@ -319,16 +319,16 @@ void SparsePoseGraph::HandleScanQueue() {
         num_scans_since_last_loop_closure_ = 0;
         run_loop_closure_ = false;
         while (!run_loop_closure_) {
-          if (scan_queue_->empty()) {
+          if (work_queue_->empty()) {
             LOG(INFO) << "We caught up. Hooray!";
-            scan_queue_.reset();
+            work_queue_.reset();
             return;
           }
-          scan_queue_->front()();
-          scan_queue_->pop_front();
+          work_queue_->front()();
+          work_queue_->pop_front();
         }
         // We have to optimize again.
-        HandleScanQueue();
+        HandleWorkQueue();
       });
 }
 
diff --git a/cartographer/mapping_2d/sparse_pose_graph.h b/cartographer/mapping_2d/sparse_pose_graph.h
index 7f3c38a..1e927b7 100644
--- a/cartographer/mapping_2d/sparse_pose_graph.h
+++ b/cartographer/mapping_2d/sparse_pose_graph.h
@@ -142,8 +142,8 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
       REQUIRES(mutex_);
 
   // Registers the callback to run the optimization once all constraints have
-  // been computed, that will also do all work that queue up in 'scan_queue_'.
-  void HandleScanQueue() REQUIRES(mutex_);
+  // been computed, that will also do all work that queue up in 'work_queue_'.
+  void HandleWorkQueue() REQUIRES(mutex_);
 
   // Waits until we caught up (i.e. nothing is waiting to be scheduled), and
   // all computations have finished.
@@ -166,9 +166,9 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
   const mapping::proto::SparsePoseGraphOptions options_;
   common::Mutex mutex_;
 
-  // If it exists, further scans must be added to this queue, and will be
+  // If it exists, further work items must be added to this queue, and will be
   // considered later.
-  std::unique_ptr<std::deque<std::function<void()>>> scan_queue_
+  std::unique_ptr<std::deque<std::function<void()>>> work_queue_
       GUARDED_BY(mutex_);
 
   // How our various trajectories are related.
diff --git a/cartographer/mapping_3d/sparse_pose_graph.cc b/cartographer/mapping_3d/sparse_pose_graph.cc
index 2c59b0f..9cef64f 100644
--- a/cartographer/mapping_3d/sparse_pose_graph.cc
+++ b/cartographer/mapping_3d/sparse_pose_graph.cc
@@ -49,7 +49,7 @@ SparsePoseGraph::SparsePoseGraph(
 SparsePoseGraph::~SparsePoseGraph() {
   WaitForAllComputations();
   common::MutexLocker locker(&mutex_);
-  CHECK(scan_queue_ == nullptr);
+  CHECK(work_queue_ == nullptr);
 }
 
 std::vector<mapping::SubmapId> SparsePoseGraph::GrowSubmapTransformsAsNeeded(
@@ -135,10 +135,10 @@ void SparsePoseGraph::AddScan(
 }
 
 void SparsePoseGraph::AddWorkItem(const std::function<void()>& work_item) {
-  if (scan_queue_ == nullptr) {
+  if (work_queue_ == nullptr) {
     work_item();
   } else {
-    scan_queue_->push_back(work_item);
+    work_queue_->push_back(work_item);
   }
 }
 
@@ -313,15 +313,15 @@ void SparsePoseGraph::ComputeConstraintsForScan(
       num_scans_since_last_loop_closure_ > options_.optimize_every_n_scans()) {
     CHECK(!run_loop_closure_);
     run_loop_closure_ = true;
-    // If there is a 'scan_queue_' already, some other thread will take care.
-    if (scan_queue_ == nullptr) {
-      scan_queue_ = common::make_unique<std::deque<std::function<void()>>>();
-      HandleScanQueue();
+    // If there is a 'work_queue_' already, some other thread will take care.
+    if (work_queue_ == nullptr) {
+      work_queue_ = common::make_unique<std::deque<std::function<void()>>>();
+      HandleWorkQueue();
     }
   }
 }
 
-void SparsePoseGraph::HandleScanQueue() {
+void SparsePoseGraph::HandleWorkQueue() {
   constraint_builder_.WhenDone(
       [this](const sparse_pose_graph::ConstraintBuilder::Result& result) {
         {
@@ -334,16 +334,16 @@ void SparsePoseGraph::HandleScanQueue() {
         num_scans_since_last_loop_closure_ = 0;
         run_loop_closure_ = false;
         while (!run_loop_closure_) {
-          if (scan_queue_->empty()) {
+          if (work_queue_->empty()) {
             LOG(INFO) << "We caught up. Hooray!";
-            scan_queue_.reset();
+            work_queue_.reset();
             return;
           }
-          scan_queue_->front()();
-          scan_queue_->pop_front();
+          work_queue_->front()();
+          work_queue_->pop_front();
         }
         // We have to optimize again.
-        HandleScanQueue();
+        HandleWorkQueue();
       });
 }
 
diff --git a/cartographer/mapping_3d/sparse_pose_graph.h b/cartographer/mapping_3d/sparse_pose_graph.h
index a128c8f..42d5a83 100644
--- a/cartographer/mapping_3d/sparse_pose_graph.h
+++ b/cartographer/mapping_3d/sparse_pose_graph.h
@@ -143,8 +143,8 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
       REQUIRES(mutex_);
 
   // Registers the callback to run the optimization once all constraints have
-  // been computed, that will also do all work that queue up in 'scan_queue_'.
-  void HandleScanQueue() REQUIRES(mutex_);
+  // been computed, that will also do all work that queue up in 'work_queue_'.
+  void HandleWorkQueue() REQUIRES(mutex_);
 
   // Waits until we caught up (i.e. nothing is waiting to be scheduled), and
   // all computations have finished.
@@ -171,9 +171,9 @@ class SparsePoseGraph : public mapping::SparsePoseGraph {
   const mapping::proto::SparsePoseGraphOptions options_;
   common::Mutex mutex_;
 
-  // If it exists, further scans must be added to this queue, and will be
+  // If it exists, further work items must be added to this queue, and will be
   // considered later.
-  std::unique_ptr<std::deque<std::function<void()>>> scan_queue_
+  std::unique_ptr<std::deque<std::function<void()>>> work_queue_
       GUARDED_BY(mutex_);
 
   // How our various trajectories are related.