diff --git a/src/micropolisj/engine/MapScanner.java b/src/micropolisj/engine/MapScanner.java
index 7aa2db0..a7ccd94 100644
--- a/src/micropolisj/engine/MapScanner.java
+++ b/src/micropolisj/engine/MapScanner.java
@@ -109,7 +109,7 @@ class MapScanner extends TileBehavior
 
 	boolean setZonePower()
 	{
-		boolean oldPower = (rawTile & PWRBIT) == PWRBIT;
+		boolean oldPower = city.isTilePowered(xpos, ypos);
 		boolean newPower = (
 			tile == NUCLEAR ||
 			tile == POWERPLANT ||
@@ -118,12 +118,12 @@ class MapScanner extends TileBehavior
 
 		if (newPower && !oldPower)
 		{
-			city.setTile(xpos, ypos, (char) (rawTile | PWRBIT));
+			city.setTilePower(xpos, ypos, true);
 			city.powerZone(xpos, ypos, getZoneSizeFor(tile));
 		}
 		else if (!newPower && oldPower)
 		{
-			city.setTile(xpos, ypos, (char) (rawTile & (~PWRBIT)));
+			city.setTilePower(xpos, ypos, false);
 			city.shutdownZone(xpos, ypos, getZoneSizeFor(tile));
 		}
 
@@ -172,9 +172,8 @@ class MapScanner extends TileBehavior
 			}
 		}
 
-		// refresh rawTile, tile
-		this.rawTile = city.map[ypos][xpos];
-		this.tile = (char) (rawTile & LOMASK);
+		// refresh own tile property
+		this.tile = city.getTile(xpos, ypos);
 
 		setZonePower();
 		return true;
@@ -798,8 +797,10 @@ class MapScanner extends TileBehavior
 		{
 			// downgrade from full-size zone to 8 little houses
 
-			int pwrBit = (rawTile & PWRBIT);
-			city.setTile(xpos, ypos, (char)(RESCLR | pwrBit));
+			boolean pwr = city.isTilePowered(xpos, ypos);
+			city.setTile(xpos, ypos, RESCLR);
+			city.setTilePower(xpos, ypos, pwr);
+
 			for (int x = xpos-1; x <= xpos+1; x++)
 			{
 				for (int y = ypos-1; y <= ypos+1; y++)
diff --git a/src/micropolisj/engine/Micropolis.java b/src/micropolisj/engine/Micropolis.java
index 93535c7..faf978c 100644
--- a/src/micropolisj/engine/Micropolis.java
+++ b/src/micropolisj/engine/Micropolis.java
@@ -464,8 +464,15 @@ public class Micropolis
 		return (getTileRaw(xpos, ypos) & PWRBIT) == PWRBIT;
 	}
 
+	/**
+	 * Note: this method clears the PWRBIT of the given location.
+	 */
 	public void setTile(int xpos, int ypos, char newTile)
 	{
+		// check to make sure we aren't setting an upper bit using
+		// this method
+		assert (newTile & LOMASK) == newTile;
+
 		if (map[ypos][xpos] != newTile)
 		{
 			map[ypos][xpos] = newTile;
@@ -473,6 +480,11 @@ public class Micropolis
 		}
 	}
 
+	public void setTilePower(int xpos, int ypos, boolean power)
+	{
+		map[ypos][xpos] = (char)(map[ypos][xpos] & (~PWRBIT) | (power ? PWRBIT : 0));
+	}
+
 	final public boolean testBounds(int xpos, int ypos)
 	{
 		return xpos >= 0 && xpos < getWidth() &&
diff --git a/src/micropolisj/engine/TerrainBehavior.java b/src/micropolisj/engine/TerrainBehavior.java
index 6452c57..1907349 100644
--- a/src/micropolisj/engine/TerrainBehavior.java
+++ b/src/micropolisj/engine/TerrainBehavior.java
@@ -203,9 +203,7 @@ class TerrainBehavior extends TileBehavior
 
 		if (tden != newLevel)
 		{
-			int z = (((rawTile & LOMASK) - ROADBASE) & 15) + TRAFFIC_DENSITY_TAB[newLevel];
-			z += rawTile & ALLBITS;
-
+			int z = ((tile - ROADBASE) & 15) + TRAFFIC_DENSITY_TAB[newLevel];
 			city.setTile(xpos, ypos, (char) z);
 		}
 	}
diff --git a/src/micropolisj/engine/TileBehavior.java b/src/micropolisj/engine/TileBehavior.java
index 24d3956..021e757 100644
--- a/src/micropolisj/engine/TileBehavior.java
+++ b/src/micropolisj/engine/TileBehavior.java
@@ -18,7 +18,6 @@ public abstract class TileBehavior
 	int xpos;
 	int ypos;
 	int tile;
-	int rawTile;
 
 	protected TileBehavior(Micropolis city)
 	{
@@ -30,8 +29,7 @@ public abstract class TileBehavior
 	{
 		this.xpos = xpos;
 		this.ypos = ypos;
-		this.rawTile = city.getTileRaw(xpos, ypos);
-		this.tile = rawTile & LOMASK;
+		this.tile = city.getTile(xpos, ypos);
 		apply();
 	}