Gerenciar Sessão do Driver de Forma simultane

Galera, boa tarde!

De qual forma posso gerenciar minha sessão do Driver do Selenium de forma inteligente, que eu consiga rodar varios testes ao mesmo tempo e ele não se perca?

Hoje minha classe está assim que gerencia o drive.

package mapfre.automationTestsMcc.utils.config;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;
import mapfre.automationTestsMcc.utils.enums.BrowserEnum;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.edge.EdgeDriver;
import org.openqa.selenium.firefox.FirefoxBinary;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.firefox.FirefoxProfile;
import org.openqa.selenium.ie.InternetExplorerDriver;
import org.openqa.selenium.remote.CapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.safari.SafariDriver;

public class ConfigFactory {

    public static WebDriver getWebDriver(final BrowserEnum browser) throws IOException{
        DesiredCapabilities capabilities = null;
        WebDriver driver = null;

        final Properties properties = getProperties();

        switch(browser){
            case FIREFOX:{
                final File pathBinary = new File(properties.getProperty("firefox.webdriver.path"));
                final FirefoxBinary firefoxBinary = new FirefoxBinary(pathBinary);
                final FirefoxProfile firefoxProfile = new FirefoxProfile();
                firefoxProfile.setPreference(FirefoxProfile.PORT_PREFERENCE, 9876);  
                driver = new FirefoxDriver(firefoxBinary, firefoxProfile);
                break;
            }
            case CHROME:{
                loadDriver(browser, "chromedriver.exe");

                driver = new ChromeDriver();
                ChromeOptions options = new ChromeOptions();
                options.addArguments("no-sandbox");
                break;
            }
            case IE: {
                loadDriver(browser, "IEDriverServer.exe");

                capabilities = DesiredCapabilities.internetExplorer();
                capabilities.setCapability(InternetExplorerDriver.REQUIRE_WINDOW_FOCUS, true);
                capabilities.setCapability(InternetExplorerDriver.INTRODUCE_FLAKINESS_BY_IGNORING_SECURITY_DOMAINS, true);
                capabilities.setCapability(InternetExplorerDriver.IGNORE_ZOOM_SETTING, true);
                capabilities.setCapability(CapabilityType.ACCEPT_SSL_CERTS, true);


                driver = new InternetExplorerDriver(capabilities);
                break;
            }
            case IE11: {
                loadDriver(browser, "IEDriverServer.exe");

                capabilities = DesiredCapabilities.internetExplorer();
                capabilities.setCapability(InternetExplorerDriver.REQUIRE_WINDOW_FOCUS, true);
                capabilities.setCapability(InternetExplorerDriver.INTRODUCE_FLAKINESS_BY_IGNORING_SECURITY_DOMAINS, true);
                capabilities.setCapability(InternetExplorerDriver.IGNORE_ZOOM_SETTING, true);
                capabilities.setCapability(CapabilityType.ACCEPT_SSL_CERTS, true);
                capabilities.setCapability("initialBrowserUrl", "http://www.google.com");

                driver = new InternetExplorerDriver(capabilities);
                break;
            }
            case SAFARI: {
                driver = new SafariDriver();
                break;
            }
            case EDGE: {
                System.setProperty(browser.getDriver(), properties.getProperty("edge.webdriver.path"));

                DesiredCapabilities caps = new DesiredCapabilities();
                caps.setCapability(CapabilityType.BROWSER_NAME, "MicrosoftEdge");
                caps.setCapability(CapabilityType.VERSION, "13");
                caps.setCapability(CapabilityType.PLATFORM, "Windows 10");

                driver = new EdgeDriver(caps);
                break;
            }
        };

        return driver;
    }

    private static void loadDriver(final BrowserEnum browser, final String webDriver) {
        if(!webDriver.isEmpty()){
            final File file = new File("recipes" + File.separator + "drivers"+ File.separator + webDriver);
            System.setProperty(browser.getDriver(), file.getAbsolutePath());
        }
    }

    private static Properties getProperties() throws IOException {
        final Properties props = new Properties();
        final FileInputStream file = new FileInputStream("."+ File.separator +"src" + File.separator + "test"+ File.separator +"java"+ File.separator +"browserConfig.properties");
        props.load(file);
        return props;
    }
}

Lembrando que estou utilizando em 99% das vezes o Firefox.