diff --git a/control/src/stop_signs.rs b/control/src/stop_signs.rs
index 6b57588287..98078d8ea3 100644
--- a/control/src/stop_signs.rs
+++ b/control/src/stop_signs.rs
@@ -220,12 +220,3 @@ impl ControlStopSign {
         Ok(())
     }
 }
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn ordering() {
-        use stop_signs::TurnPriority;
-        assert!(TurnPriority::Priority > TurnPriority::Yield);
-    }
-}
diff --git a/sim/tests/completion.rs b/sim/tests/completion.rs
deleted file mode 100644
index 9b40577747..0000000000
--- a/sim/tests/completion.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-extern crate abstutil;
-extern crate control;
-extern crate map_model;
-extern crate sim;
-
-#[test]
-fn aorta_model_completes() {
-    let (map, control_map, mut sim) = sim::load(
-        sim::SimFlags::for_test("aorta_model_completes"),
-        Some(sim::Tick::from_seconds(30)),
-        &mut abstutil::Timer::new("setup test"),
-    );
-    sim.small_spawn(&map);
-    sim.run_until_done(&map, &control_map, Box::new(|_sim| {}));
-}
-
-// TODO other tests (not completion) to add:
-// - different behavior (stopping or not) at stop signs
diff --git a/sim/tests/determinism.rs b/sim/tests/determinism.rs
deleted file mode 100644
index 51995f2c28..0000000000
--- a/sim/tests/determinism.rs
+++ /dev/null
@@ -1,97 +0,0 @@
-extern crate abstutil;
-extern crate control;
-extern crate map_model;
-extern crate sim;
-
-#[test]
-fn serialization() {
-    let (map, _, mut sim) = sim::load(
-        sim::SimFlags::for_test("serialization"),
-        None,
-        &mut abstutil::Timer::new("setup test"),
-    );
-    sim.small_spawn(&map);
-
-    // Does savestating produce the same string?
-    let save1 = abstutil::to_json(&sim);
-    let save2 = abstutil::to_json(&sim);
-    assert_eq!(save1, save2);
-}
-
-#[test]
-fn from_scratch() {
-    println!("Creating two simulations");
-    let (map, control_map, mut sim1) = sim::load(
-        sim::SimFlags::for_test("from_scratch_1"),
-        None,
-        &mut abstutil::Timer::new("setup test"),
-    );
-    let mut sim2 = sim::Sim::new(&map, "from_scratch_2".to_string(), Some(42), None);
-    sim1.small_spawn(&map);
-    sim2.small_spawn(&map);
-
-    for _ in 1..600 {
-        if sim1 != sim2 {
-            // TODO need to sort dicts in json output to compare
-            panic!(
-                "sim state differs between {} and {}",
-                sim1.save(),
-                sim2.save()
-            );
-        }
-        sim1.step(&map, &control_map);
-        sim2.step(&map, &control_map);
-    }
-}
-
-#[test]
-fn with_savestating() {
-    println!("Creating two simulations");
-    let (map, control_map, mut sim1) = sim::load(
-        sim::SimFlags::for_test("with_savestating_1"),
-        None,
-        &mut abstutil::Timer::new("setup test"),
-    );
-    let mut sim2 = sim::Sim::new(&map, "with_savestating_2".to_string(), Some(42), None);
-    sim1.small_spawn(&map);
-    sim2.small_spawn(&map);
-
-    for _ in 1..600 {
-        sim1.step(&map, &control_map);
-        sim2.step(&map, &control_map);
-    }
-
-    if sim1 != sim2 {
-        panic!(
-            "sim state differs between {} and {}",
-            sim1.save(),
-            sim2.save()
-        );
-    }
-
-    let sim1_save = sim1.save();
-
-    for _ in 1..60 {
-        sim1.step(&map, &control_map);
-    }
-
-    if sim1 == sim2 {
-        panic!(
-            "sim state unexpectly the same -- {} and {}",
-            sim1.save(),
-            sim2.save()
-        );
-    }
-
-    let sim3: sim::Sim =
-        sim::Sim::load(sim1_save.clone(), "with_savestating_3".to_string()).unwrap();
-    if sim3 != sim2 {
-        panic!(
-            "sim state differs between {} and {}",
-            sim3.save(),
-            sim2.save()
-        );
-    }
-
-    std::fs::remove_file(sim1_save).unwrap();
-}
diff --git a/tests/src/main.rs b/tests/src/main.rs
index cc29666cc1..6faa638863 100644
--- a/tests/src/main.rs
+++ b/tests/src/main.rs
@@ -10,6 +10,8 @@ extern crate yansi;
 mod map_conversion;
 mod physics;
 mod runner;
+mod sim_completion;
+mod sim_determinism;
 
 use structopt::StructOpt;
 
@@ -26,6 +28,8 @@ fn main() {
 
     map_conversion::run(t.suite("map_conversion"));
     physics::run(t.suite("physics"));
+    sim_completion::run(t.suite("sim_completion"));
+    sim_determinism::run(t.suite("sim_determinism"));
 
     t.done();
 }
diff --git a/tests/src/sim_completion.rs b/tests/src/sim_completion.rs
new file mode 100644
index 0000000000..e3bc7fbf6b
--- /dev/null
+++ b/tests/src/sim_completion.rs
@@ -0,0 +1,21 @@
+use abstutil::Timer;
+use runner::TestRunner;
+use sim;
+
+pub fn run(t: &mut TestRunner) {
+    t.run_slow(
+        "small_spawn_completes",
+        Box::new(|_| {
+            let (map, control_map, mut sim) = sim::load(
+                sim::SimFlags::for_test("aorta_model_completes"),
+                Some(sim::Tick::from_seconds(30)),
+                &mut Timer::new("setup test"),
+            );
+            sim.small_spawn(&map);
+            sim.run_until_done(&map, &control_map, Box::new(|_sim| {}));
+        }),
+    );
+}
+
+// TODO other tests (not completion) to add:
+// - different behavior (stopping or not) at stop signs
diff --git a/tests/src/sim_determinism.rs b/tests/src/sim_determinism.rs
new file mode 100644
index 0000000000..de7d724972
--- /dev/null
+++ b/tests/src/sim_determinism.rs
@@ -0,0 +1,104 @@
+use abstutil::Timer;
+use runner::TestRunner;
+use sim;
+
+pub fn run(t: &mut TestRunner) {
+    t.run_slow(
+        "serialization",
+        Box::new(|_| {
+            let (map, _, mut sim) = sim::load(
+                sim::SimFlags::for_test("serialization"),
+                None,
+                &mut Timer::new("setup test"),
+            );
+            sim.small_spawn(&map);
+
+            // Does savestating produce the same string?
+            let save1 = abstutil::to_json(&sim);
+            let save2 = abstutil::to_json(&sim);
+            assert_eq!(save1, save2);
+        }),
+    );
+
+    t.run_slow(
+        "from_scratch",
+        Box::new(|_| {
+            println!("Creating two simulations");
+            let (map, control_map, mut sim1) = sim::load(
+                sim::SimFlags::for_test("from_scratch_1"),
+                None,
+                &mut Timer::new("setup test"),
+            );
+            let mut sim2 = sim::Sim::new(&map, "from_scratch_2".to_string(), Some(42), None);
+            sim1.small_spawn(&map);
+            sim2.small_spawn(&map);
+
+            for _ in 1..600 {
+                if sim1 != sim2 {
+                    // TODO need to sort dicts in json output to compare
+                    panic!(
+                        "sim state differs between {} and {}",
+                        sim1.save(),
+                        sim2.save()
+                    );
+                }
+                sim1.step(&map, &control_map);
+                sim2.step(&map, &control_map);
+            }
+        }),
+    );
+
+    t.run_slow(
+        "with_savestating",
+        Box::new(|_| {
+            println!("Creating two simulations");
+            let (map, control_map, mut sim1) = sim::load(
+                sim::SimFlags::for_test("with_savestating_1"),
+                None,
+                &mut Timer::new("setup test"),
+            );
+            let mut sim2 = sim::Sim::new(&map, "with_savestating_2".to_string(), Some(42), None);
+            sim1.small_spawn(&map);
+            sim2.small_spawn(&map);
+
+            for _ in 1..600 {
+                sim1.step(&map, &control_map);
+                sim2.step(&map, &control_map);
+            }
+
+            if sim1 != sim2 {
+                panic!(
+                    "sim state differs between {} and {}",
+                    sim1.save(),
+                    sim2.save()
+                );
+            }
+
+            let sim1_save = sim1.save();
+
+            for _ in 1..60 {
+                sim1.step(&map, &control_map);
+            }
+
+            if sim1 == sim2 {
+                panic!(
+                    "sim state unexpectly the same -- {} and {}",
+                    sim1.save(),
+                    sim2.save()
+                );
+            }
+
+            let sim3: sim::Sim =
+                sim::Sim::load(sim1_save.clone(), "with_savestating_3".to_string()).unwrap();
+            if sim3 != sim2 {
+                panic!(
+                    "sim state differs between {} and {}",
+                    sim3.save(),
+                    sim2.save()
+                );
+            }
+
+            std::fs::remove_file(sim1_save).unwrap();
+        }),
+    );
+}