diff --git a/tests/_metrics/test_tp_utils.py b/tests/_metrics/test_tp_utils.py
new file mode 100644
index 00000000..be3a9572
--- /dev/null
+++ b/tests/_metrics/test_tp_utils.py
@@ -0,0 +1,55 @@
+import pytest
+
+from pandas.testing import assert_frame_equal
+from pytest_lazyfixture import lazy_fixture
+
+from transport_performance._metrics.tp_utils import (
+    _transport_performance_pandas,
+)
+
+# import metrics fixtures via pytest_plugins
+pytest_plugins = ["tests._metrics.metrics_fixtures"]
+
+
+class TestTransportPerformancePandas:
+    """Unit tests for _transport_performance_pandas()."""
+
+    @pytest.mark.parametrize(
+        "tt_path",
+        [lazy_fixture("tt_fixture"), lazy_fixture("multi_tt_fixture")],
+    )
+    def test__transport_performance_pandas(
+        self,
+        centroid_gdf_fixture,
+        pop_gdf_fixture,
+        tt_path,
+        expected_transport_performance,
+    ) -> None:
+        """Test main behaviour of _transport_performance_pandas().
+
+        Test with both single and multiple travel time input parquet files.
+
+        Parameters
+        ----------
+        centroid_gdf_fixture
+            A mock centroid test fixture.
+        pop_gdf_fixture
+            A mock population test fixture.
+        tt_path
+            A path to mock travel time fixture(s).
+        expected_transport_performance
+            A mock travel time test fixture.
+
+        """
+        # call transport_performance() using the test fixtures
+        tp_df = _transport_performance_pandas(
+            tt_path,
+            centroid_gdf_fixture,
+            pop_gdf_fixture,
+            travel_time_threshold=3,
+            distance_threshold=0.11,
+        )
+
+        # upack expected results and confirm equivalence
+        test_subset_cols, expected_tp, _ = expected_transport_performance
+        assert_frame_equal(tp_df[test_subset_cols], expected_tp)