From 38c71bf270a31e6b36e48882da2d6e656e5d50de Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 16 Jul 2026 13:20:13 +0000
Subject: [PATCH 1/2] Initial plan


From 2dda67e67f228affa4da46beecd89dc1ae8535e0 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 16 Jul 2026 13:25:00 +0000
Subject: [PATCH 2/2] Fix black formatting in trip_scheduling_choice files

---
 .../abm/models/trip_scheduling_choice.py      | 13 ++++++++--
 .../test_misc/test_trip_scheduling_choice.py  | 24 +++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/activitysim/abm/models/trip_scheduling_choice.py b/activitysim/abm/models/trip_scheduling_choice.py
index 81d908ef1b..fb54ced692 100644
--- a/activitysim/abm/models/trip_scheduling_choice.py
+++ b/activitysim/abm/models/trip_scheduling_choice.py
@@ -276,7 +276,12 @@ def run_trip_scheduling_choice(
             choosers,
             chunk_trace_label,
             chunk_sizer,
-        ) in chunk.adaptive_chunked_choosers(state, indirect_tours, trace_label):
+        ) in chunk.adaptive_chunked_choosers(
+            state,
+            indirect_tours,
+            trace_label,
+            explicit_chunk_size=model_settings.explicit_chunk,
+        ):
             # Sort the choosers and get the schedule alternatives
             choosers = choosers.sort_index()
             schedules = generate_schedule_alternatives(choosers).sort_index()
@@ -350,7 +355,11 @@ class TripSchedulingChoiceSettings(LogitComponentSettings, extra="forbid"):
     Settings for the `trip_scheduling_choice` component.
     """
 
-    pass
+    explicit_chunk: float = 0
+    """
+    If > 0, use this chunk size instead of adaptive chunking.
+    If less than 1, use this fraction of the total number of rows.
+    """
 
 
 @workflow.step
diff --git a/activitysim/abm/test/test_misc/test_trip_scheduling_choice.py b/activitysim/abm/test/test_misc/test_trip_scheduling_choice.py
index 6823a5b123..9159044c40 100644
--- a/activitysim/abm/test/test_misc/test_trip_scheduling_choice.py
+++ b/activitysim/abm/test/test_misc/test_trip_scheduling_choice.py
@@ -4,6 +4,7 @@
 import os
 from pathlib import Path
 
+from pandas.testing import assert_frame_equal
 
 from activitysim.abm.models import trip_scheduling_choice as tsc
 from activitysim.abm.tables.skims import skim_dict
@@ -285,3 +286,26 @@ def test_run_trip_scheduling_choice(model_spec, tours, skims, locals_dict):
 
     # check that tours with no inbound stops have zero inbound duration
     assert out_tours[tsc.IB_DURATION].mask(in_tours[tsc.HAS_IB_STOPS], 0).sum() == 0
+
+    # confirm explicit chunking is supported and doesn't affect results
+    state.settings.chunk_training_mode = "explicit"
+
+    model_settings_explicit_chunk = tsc.TripSchedulingChoiceSettings(
+        **{
+            "SPEC": "placeholder.csv",
+            "explicit_chunk": 2,
+            "compute_settings": {
+                "protect_columns": ["origin", "destination", "schedule_id"]
+            },
+        }
+    )
+    out_tours_chunked = tsc.run_trip_scheduling_choice(
+        state,
+        model_spec,
+        in_tours.copy(deep=True),
+        skims,
+        locals_dict,
+        trace_label="PyTest Trip Scheduling",
+        model_settings=model_settings_explicit_chunk,
+    )
+    assert_frame_equal(out_tours, out_tours_chunked)