Can I take my girlfriend with me to work as a passenger?

I'm an electrician and tomorrow I'm going on a short tour of 6 hours to the customer, doing a little something with the laptop on a system and then I'm going home again, i.e. I would drive for a short 6 hours to do my job and then back to the company. My girlfriend is on vacation and would go with her so that I wouldn't be all alone on the trip. To be honest, that would help me personally with waxing / staying fit while driving. How does the whole insurance look like?

I'm not sure, but I don't think she's allowed to ride. The best thing to do is just call the boss and ask.

I will allow you to do that - the question is how the boss and the insurance company see it. In any case, get the boss's written approval. If you are involved in an accident, it may otherwise become a big problem.

It wouldn't be worth it.

Your boss has to decide that. Basically, with such stories, it is easy to have problems with the insurance

I have been running my own electrical installation company for 7 years and I've already had this discussion with 3 of my employees.
My take on this is:

As long as it doesn't affect the work performance of my worker, I don't care.
I was even positively surprised by one of my employees, as he managed 1.5 times his workload that day, as his girlfriend did the bureaucratic tasks while driving in the passenger seat.

If I were you, I would talk to your manager just to be on the safe side.

You have to ask the boss. If they agree, there should be no problems.