How to scare employer with legal issue?

Hi,

My workplace is trying to get me to do something which endangers my life and the lives of others.

I work as a tour guide, and I'm asked to drive and guide guests for 11 hours, including through mountain tunnels.

A few months ago, I brought up this issue with my employers and they said they would limit my driving tours to 7 hours (actually 9+ sometimes), but the other driver quit and they are pressuring me to do the long driving tours.

I've told them that there is a risk that I will fall asleep while driving (I've actually nodded off while driving in the past). They are still asking me to do this tour.

At this stage, it is just someone in the office. It hasn't got to the point where my actual boss or manager is asking me. However, if it gets to that stage and they refuse to listen, I'm looking for an option of getting a letter from a lawyer or someone that will scare them off from asking me.

I've already been to the local free legal advice place in the past and they only allow one visit.

Is there a cheap way of just getting some paper officially done up that will be enough to scare them off? Regardless, I will refuse to do the work. I don't want to waste any of my money on them. I'm supposed to make money from the company, not spend my money on them.

Conversely, is there some law site where I can take quotes about Japanese law to send them?

by JimIsGreaterThanJack