The world's first numerical speed limit was introduced in the United Kingdom in 1861. The Locomotive Act 1861 introduced a speed limit of 10mph on the public highway and 5mph in villages, towns or cities. You can read the relevant provision of the Act here.

This Act preceded the modern automobile - a motorized vehicle powered by an internal combustion engine. The Act was largely aimed at steam powered vehicles such as traction engines. You'll note that much of the Act deals with the size and weight of steam powered road locomotives, and regulates where they can travel. You'll also note that s9 of the Act states that each locomotive must have at least two people operating it.

I'm afraid that I'm not sure if there were any protests about this Act. I doubt that there were many (or any) protests, however. Parliament did not take long to impose more stringent rules on road locomotives. The Locomotive Act 1865 restricted speed limits further - to 4mph on the public highway and 2mph in towns. This Act also specified that each locomotive be led by a man holding a red flag aloft.