diff --git dataobj/settings.cc dataobj/settings.cc
index ddccff1ec3..3f4d1295fe 100644
--- dataobj/settings.cc
+++ dataobj/settings.cc
@@ -745,8 +745,12 @@ void settings_t::rdwr(loadsave_t *file)
 		}
 		if(file->is_version_atleast(102, 3)) {
 			// network stuff
-			random_counter = get_random_seed( );
-			file->rdwr_long( random_counter );
+			// Superseded by simrand_rdwr in newer versions
+			if (file->is_version_less(122, 1)) {
+				random_counter = get_random_seed( );
+				file->rdwr_long( random_counter );
+			}
+
 			if(  !env_t::networkmode  ||  env_t::server  ) {
 				frames_per_second = clamp(env_t::fps, 5u, 100u); // update it on the server to the current setting
 				frames_per_step = env_t::network_frames_per_step;
diff --git player/ai_passenger.cc player/ai_passenger.cc
index 6ed724c2c6..162bb18aa2 100644
--- player/ai_passenger.cc
+++ player/ai_passenger.cc
@@ -1436,8 +1436,15 @@ void ai_passenger_t::rdwr(loadsave_t *file)
 		k3d.rdwr(file);
 		ziel = fabrik_t::get_fab(k3d.get_2d() );
 	}
-}
 
+	if (file->is_version_atleast(122, 1)) {
+		plainstring road_vehicle_name = road_vehicle ? road_vehicle->get_name() : "";
+		file->rdwr_str(road_vehicle_name);
+		if (file->is_loading() && road_vehicle_name != "") {
+			road_vehicle = vehicle_builder_t::get_info(road_vehicle_name);
+		}
+	}
+}
 
 
 /**
@@ -1458,7 +1465,11 @@ void ai_passenger_t::report_vehicle_problem(convoihandle_t cnv,const koord3d zie
 
 void ai_passenger_t::finish_rd()
 {
-	road_vehicle = vehikel_search( road_wt, 50, 80, goods_manager_t::passengers, false);
+	if (!road_vehicle) {
+		dbg->warning("ai_passenger_t::finish_rd", "Default road vehicle could not be loaded, searching for one...");
+		road_vehicle = vehikel_search( road_wt, 50, 80, goods_manager_t::passengers, false);
+	}
+
 	if (road_vehicle == NULL) {
 		// reset state
 		end_stadt = NULL;
diff --git simworld.cc simworld.cc
index bfcfd089e3..ab0ffbb674 100644
--- simworld.cc
+++ simworld.cc
@@ -4780,11 +4780,17 @@ DBG_MESSAGE("karte_t::save(loadsave_t *file)", "start");
 			settings.set_player_type(i, player_t::EMPTY);
 		}
 	}
+
 	settings.rdwr(file);
+
 	for(  int i=0;  i<MAX_PLAYER_COUNT;  i++  ) {
 		settings.set_player_type(i, old_players[i]);
 	}
 
+	if (file->is_version_atleast(122, 1)) {
+		simrand_rdwr(file);
+	}
+
 	file->rdwr_long(ticks);
 	file->rdwr_long(last_month);
 	file->rdwr_long(last_year);
@@ -5352,14 +5358,24 @@ void karte_t::load(loadsave_t *file)
 	dbg->warning("karte_t::load", "Fileversion: %u", file->get_version_int());
 	settings = env_t::default_settings;
 	settings.rdwr(file);
+
 	loaded_rotation = settings.get_rotation();
 
 	// some functions (finish_rd) need to know what version was loaded
 	load_version = file->get_version_int();
 
+	if (file->is_version_atleast(122, 1)) {
+		// rdwr the entire RNG sate
+		simrand_rdwr(file);
+	}
+
 	if(  env_t::networkmode  ) {
-		// to have games synchronized, transfer random counter too
-		setsimrand(settings.get_random_counter(), 0xFFFFFFFFu );
+		// To have games synchronized, transfer random counter too
+		// Superseded by simrand_rdwr in newer versions
+		if (file->is_version_less(122, 1)) {
+			setsimrand(settings.get_random_counter(), 0xFFFFFFFFu );
+		}
+
 		translator::init_custom_names(settings.get_name_language_id());
 	}
 
diff --git utils/simrandom.cc utils/simrandom.cc
index e9cea538fa..939a621c8b 100644
--- utils/simrandom.cc
+++ utils/simrandom.cc
@@ -8,6 +8,8 @@
 #include <time.h>
 #include "simrandom.h"
 #include "../sys/simsys.h"
+#include "../dataobj/loadsave.h"
+
 
 /* This is the mersenne random generator: More random and faster! */
 
@@ -18,8 +20,8 @@
 #define UPPER_MASK 0x80000000UL /* most significant w-r bits */
 #define LOWER_MASK 0x7fffffffUL /* least significant r bits */
 
-static unsigned long mersenne_twister[MERSENNE_TWISTER_N]; // the array for the state vector
-static int mersenne_twister_index = MERSENNE_TWISTER_N + 1; // mersenne_twister_index==N+1 means mersenne_twister[N] is not initialized
+static uint32 mersenne_twister[MERSENNE_TWISTER_N]; // the array for the state vector
+static uint32 mersenne_twister_index = MERSENNE_TWISTER_N + 1; // mersenne_twister_index==N+1 means mersenne_twister[N] is not initialized
 
 static uint8 random_origin = 0;
 
@@ -87,7 +89,7 @@ uint32 simrand_plain()
 
 	/* Tempering */
 	y ^= (y >> 11);
-	y ^= (y << 7) & 0x9d2c5680UL;
+	y ^= (y <<  7) & 0x9d2c5680UL;
 	y ^= (y << 15) & 0xefc60000UL;
 	y ^= (y >> 18);
 
@@ -107,6 +109,20 @@ uint32 simrand(const uint32 max)
 }
 
 
+void simrand_rdwr(loadsave_t *file)
+{
+	xml_tag_t t(file, "simrand");
+
+	// rdwr index
+	file->rdwr_long(mersenne_twister_index);
+
+	// rdwr state vector
+	for (uint32 i=0; i<MERSENNE_TWISTER_N; ++i) {
+		file->rdwr_long(mersenne_twister[i]);
+	}
+}
+
+
 void clear_random_mode( uint16 mode )
 {
 	random_origin &= ~mode;
diff --git utils/simrandom.h utils/simrandom.h
index e7ecd2cf60..97bf076a7d 100644
--- utils/simrandom.h
+++ utils/simrandom.h
@@ -7,9 +7,13 @@
 #define UTILS_SIMRANDOM_H
 
 
-#include <stddef.h>
 #include "../simtypes.h"
 
+#include <cstddef>
+
+
+class loadsave_t;
+
 
 uint32 get_random_seed();
 
@@ -27,6 +31,9 @@ uint32 simrand(const uint32 max);
 /* generates a random number on [0,0xFFFFFFFFu]-interval */
 uint32 simrand_plain();
 
+/// reads/writes the sate of the random number generator
+void simrand_rdwr(loadsave_t *file);
+
 double perlin_noise_2D(const double x, const double y, const double persistence);
 
 // for network debugging, i.e. finding hidden simrands in wrong places