public static boolean canMove4Way(Collision start, Collision dest, Direction destApproach)
	{
		if (isBlocked(dest))
		{
			return false;
		}
		
		switch (destApproach)
		{
			case NORTH:
				return !(dest.has(SOUTH) || start.has(NORTH));
			case EAST:
				return !(dest.has(WEST) || start.has(EAST));
			case SOUTH:
				return !(dest.has(NORTH) || start.has(SOUTH));
			case WEST:
				return !(dest.has(EAST) || start.has(WEST));
			default:
				return false;
		}
	}