diff --git a/lib/stop_times.js b/lib/stop_times.js
index 460331c..008093d 100644
--- a/lib/stop_times.js
+++ b/lib/stop_times.js
@@ -108,6 +108,9 @@ AND "${opt.schema}".stop_times.stop_sequence = t.stop_sequence;
 
 CREATE INDEX ON "${opt.schema}".stop_times (stop_sequence_consec);
 CREATE INDEX ON "${opt.schema}".stop_times (trip_id, stop_sequence_consec);
+CREATE INDEX ON "${opt.schema}".stop_times (arrival_time DESC NULLS LAST);
+CREATE INDEX ON "${opt.schema}".stop_times (departure_time DESC NULLS LAST);
+-- todo: are these two necessary?
 CREATE INDEX ON "${opt.schema}".stop_times (arrival_time);
 CREATE INDEX ON "${opt.schema}".stop_times (departure_time);