Don't you think that he will ask why? What should the OP say then?

@Mawg I'm just answering the question asked, not making up new ones. What if he asks him what is for dinner?

@Kilisi - The difference is that why is a reasonable question to expect someone may ask when ending a paid relationship.

@IDrinkandIKnowThings you argue over other peoples personal belongings? Either way not part of the question.... unless you've made up your own question somewhere and accidentally commented here?

@Kilisi - Given that OP has just dramatically disadvantaged the ride-sharer, I think a follow-up question would be almost inevitable.

You can all feel free to make your own answers and questions while downvoting me for not answering something that wasn't asked... I'm no stranger to lame downvotes.

@Richard "Given that OP has just dramatically disadvantaged the ride-sharer ... " Stop right there! The OP is NOT causing the ride-sharer any harm whatsoever. He is merely stopping the assistance/service he had previously been offering. The ride-sharer is no worse off than before the arrangement began. That is a VERY flawed mindset that unfortunately makes its way into far too many discussions.

When someone does something petty to you over which you have no control, it's stupid to give them a chance to rub it in. Best to just shrug it off. Pushing back is just an easy opening for them to have a dig. I wouldn't ask why, it's their car, their decision.

@WesleyLong - If you stop a pre-existing arrangement, you're harming the person who was expecting the arrangement to continue (in the same way that you'd be harmed if Google decided to stop working in your country, for example). Although there's no contract in place in this particular case, expectation harm is a very real legal concept.

@Richard let's not get dramatic over it though ;)

@Kilisi - Well, for some people, being unable to arrange a ride to their workplace could result in them needing to change their employment.

@Richard I asked you not to get dramatic... but you still managed to read loss of employment into it... ahaha... have a good day, thanks for the laugh.

@Richard > Actually it should have resulted in these people not accepting the position in the first place... unless the wcarpool deal was part of the conditions, but I see no sign in the OP's questio nthat indicates this...

Regardless of the perceived fairness/morality issues of the situation, many people will feel personally offended if you abruptly put them in a position that inconveniences them. In turn, many people are uncomfortable with offending others (even if they are fully within their rights to do so). So at least by my interpretation, the OP's actual question was "how do I get rid of this guy without causing offense?". I imagine others have also interpreted the question as such. This answer does not attempt to answer that implied question, hence the bickering in the comments.

@Kilisi - I can only point to my personal experience. I once joined a company and within a few days I was providing a ride-share to a lady who lived near to me who'd been working there for several years. After a year or so, my role changed and I was no longer office-based and had to tell her that her ride would no longer be a daily thing. She quit shortly afterward due to the stress of having to resume her former commute.

@SamYonnou end of the day we have to take the OP at face value or we'll end up with answers all over the place.

@Richard why don't you build your own answer around that? Tell the OP there is immanent danger of their car sharer losing their job, becoming an alcoholic, beating their loved ones and ending up homeless.

@LaurentS. I also value directness.

@Kilisi - You forget the descent into drug use and eventual suicide.

@Richard my mistake, have a good day

@Kilisi > Yeah I kinda noticed that in many of your answers, and respect it very much although I still can't manage to be as direct as I should or would. I must admit my first reaction to your answers is often "easier to say than to do", but quickly turn into "... but he's so right" :-) In the end I've had more occasions to regret being "too nice" or "too polite" than "too direct"

@Kilisi - " I also value directness. " - Regulars on this site are all muttering something to the effect of "True words were never rendered in web browser."

@Richard - " If you stop a pre-existing arrangement, you're harming the person who was expecting the arrangement to continue." No, you have not. You are not responsible for their lack of contingency planning. Does that mean the OP can never quit his job? The OP can't move? The OP can't decide he wants to take public transportation? Can't change shifts? Can't have a sick day / vacation day? That is a PREPOSTEROUS position to take! You're usually much more reasonable than this.

@WesleyLong - As I said, if they have an expectation, even if there's no contractual basis in place, and you decide to confound that expectation then you're causing harm. Now, OP might think that the harm he's causing is minor or straight-up not his problem, but that doesn't mean that harm isn't being caused.

@Richard - Failure (or more accurately: Choosing to discontinue) to meet someone else's expectation is not nearly the same thing as causing them harm.

@WesleyLong - In law that's precisely the definition of causing "expectation harm".

@Richard - Where is the breach of contract? If the OP just stopped showing up one morning, perhaps. If they tell them, "I need to ask you to find other commuting arrangements soon," where's the harm? Every contract I've ever been involved in had sections on terminating.

@WesleyLong - As I said above (repeatedly), although there's no formal contract in place, discontinuing the current arrangement with no notice will cause a form of harm called expectation harm. Now, it's very unlikely that a court would agree that that harm was significant enough to merit compensation or that the agreement was binding enough to merit forcing OP to have to continue, but if I an expectation exists that a service (for a small payment) exists and then said service is arbitrarily removed, then harm has been caused.

@Richard - Congratulations, you've just reinstituted indentured servitude. Only a lawyer could come up with a hunk of garbage like that. However, duly noted, and if I ever have "expectational harm" thrown at me, I'll be sure to request a jury.

If the person asks "why" that is incredibly rude. If, incredibly, the person asked "Why?" simply state "It's no longer convenient." Really, it's inconceivable someone will ask "Why".