Slow down
We wish that this button would become a thing that we all used in North America and around the world. This button is located on the back seat of most taxis in Japan and when you press it, it tells the driver to slow down. What a useful addition to a taxi.
Now you do not need to have that awkward conversation with your taxi driver, just push the button and they will know what to do. It totally removes any type of unconformable contact and gives the passenger a better experience overall. Way to go Japan, you fixed the taxi industry completely.