diff --git a/openttd.c b/openttd.c
--- a/openttd.c
+++ b/openttd.c
@@ -553,6 +553,7 @@ static inline ThreadMsg OTTD_PollThreadE
  * It will stall as long as the mutex is not freed (handled) by the game */
 void OTTD_SendThreadMessage(ThreadMsg msg)
 {
+	if (_exit_game) return;
 	while (_message != 0) CSleep(10);
 
 	_message = msg;
diff --git a/openttd.dsp b/openttd.dsp
--- a/openttd.dsp
+++ b/openttd.dsp
@@ -91,23 +91,23 @@ LINK32=link.exe
 # PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
 # Begin Source File
 
-SOURCE=.\ai_build.c
+SOURCE=.\ai\trolly\build.c
 # End Source File
 # Begin Source File
 
-SOURCE=.\ai_new.c
+SOURCE=.\ai\trolly\trolly.c.c
 # End Source File
 # Begin Source File
 
-SOURCE=.\ai_old.c
+SOURCE=.\ai\default.c
 # End Source File
 # Begin Source File
 
-SOURCE=.\ai_pathfinder.c
+SOURCE=.\ai\trolly\pathfinder.c
 # End Source File
 # Begin Source File
 
-SOURCE=.\ai_shared.c
+SOURCE=.\ai\trolly\shared.c
 # End Source File
 # Begin Source File
 
@@ -494,7 +494,7 @@ SOURCE=.\window.c
 # PROP Default_Filter "h;hpp;hxx;hm;inl"
 # Begin Source File
 
-SOURCE=.\ai_new.h
+SOURCE=.\ai\trolly\trolly.h
 # End Source File
 # Begin Source File
 
diff --git a/openttd.vcproj b/openttd.vcproj
--- a/openttd.vcproj
+++ b/openttd.vcproj
@@ -162,9 +162,6 @@
 			Name="Source Files"
 			Filter="cpp;c;cxx;rc;def;r;odl;idl;hpj;bat">
 			<File
-				RelativePath="ai_old.c">
-			</File>
-			<File
 				RelativePath=".\airport.c">
 			</File>
 			<File
@@ -890,20 +887,27 @@
 			Name="AI Files"
 			Filter="">
 			<File
-				RelativePath=".\ai_build.c">
-			</File>
-			<File
-				RelativePath=".\ai_new.c">
+				RelativePath=".\ai\default\default.c">
 			</File>
-			<File
-				RelativePath=".\ai_new.h">
-			</File>
-			<File
-				RelativePath=".\ai_pathfinder.c">
-			</File>
-			<File
-				RelativePath=".\ai_shared.c">
-			</File>
+			<Filter
+				Name="trolly"
+				Filter="">
+				<File
+					RelativePath=".\ai\trolly\build.c">
+				</File>
+				<File
+					RelativePath=".\ai\trolly\pathfinder.c">
+				</File>
+				<File
+					RelativePath=".\ai\trolly\shared.c">
+				</File>
+				<File
+					RelativePath=".\ai\trolly\trolly.c">
+				</File>
+				<File
+					RelativePath=".\ai\trolly\trolly.h">
+				</File>
+			</Filter>
 		</Filter>
 		<File
 			RelativePath="icon1.ico">