Index: src/roadveh_cmd.cpp
===================================================================
--- src/roadveh_cmd.cpp	(revision 27189)
+++ src/roadveh_cmd.cpp	(working copy)
@@ -824,8 +824,9 @@
 	if (v->state >= RVSB_IN_ROAD_STOP || !IsStraightRoadTrackdir((Trackdir)(v->state & RVSB_TRACKDIR_MASK))) return;
 
 	/* Can't overtake a vehicle that is moving faster than us. If the vehicle in front is
-	 * accelerating, take the maximum speed for the comparison, else the current speed. */
-	int u_speed = u->GetAcceleration() > 0 ? u->GetCurrentMaxSpeed() : u->cur_speed;
+	 * accelerating, take the maximum speed for the comparison, else the current speed.
+	 * Original acceleration always accelerates, so always use the maximum speed. */
+	int u_speed = (_settings_game.vehicle.roadveh_acceleration_model == AM_ORIGINAL || u->GetAcceleration() > 0) ? u->GetCurrentMaxSpeed() : u->cur_speed;
 	if (u_speed >= v->GetCurrentMaxSpeed() &&
 			!(u->vehstatus & VS_STOPPED) &&
 			u->cur_speed != 0) {