To verify whether the Radio button is selected or not  using selenium WebDriver




    WebDriver driver = new FirefoxDriver();
     driver.get("http://www.travelocity.com/");
     driver.manage().timeouts().implicitlyWait(100, TimeUnit.SECONDS);

driver.findElement(By.cssSelector("input#flight-type-roundtrip")).isSelected() 
driver.findElement(By.cssSelector("input#flight-type-one-way")).isSelected()

isSelected()  method returns boolean