请看两个例句：

(1) This month, Germany’s transport minister, Alexander Dobrindt, proposed the first set of rules for autonomous vehicles. They would define the driver’s role in such cars and govern how such cars perform in crashes where lives might be lost.

(2) Driverless cars may end up being a form of public transport rather than vehicles you own, says Ryan Calo at Stanford University, California. That is happening in the UK and Singapore, where government-provided driverless vehicles are being launched. That would go down poorly in the US, however. “The idea that the government would take over driverless cars and treat them as a public good would get absolutely nowhere here,” says Calo.

节选自一篇关于“自主驾驶/自动驾驶”和“无人驾驶”车辆的文章。向各位老师请教：

一、第一句当中的would能否简单地理解成“过去将来时”，还是表推测或其它用法？

二、第二句当中第一个would是不是省略了条件句的虚拟用法？“（如果这种情况现在发生在美国）然而在美国则行不通。”

三、第二句当中的第二个would是什么用法？

四、第二句当中的第三个would是否也是省略了条件句的虚拟用法？（如果这种观点出现在美国）这种观点在这里完全行不通。