I opened a new neighborhood, moved a family into a nicely refurbished house, and had the wife take the kids to school in their nice new car. I then wanted the couple to go to Nerissa's to buy clothing, and neither of them can go to the car. Then I had them each try to call a taxi, and it never comes. What the heck? Why have they become prisoners in their own home?

Maybe something happened when mom got back from the school, maybe some portal got messed up and now your lot needs a reset...

Sounds like the portals got blocked or deleted.

OK, the school bus drops off the kids like normal. Doesn't the bus use a portal? How do I unblock a portal, or do a reset? I'll move another family into another lot and see if maybe it's a broader issue instead of one lot. I can always move the first family into another house, I guess.

I'm not even sure how to reset a lot, to be honest..but the rest of the world knows, and a portion of it should answer soon...

OK, so the new neighbors can't leave their lot, either, so the problem isn't a portal. I love a mystery. I hope these people can order groceries, or they will eventually starve.

For portals you can grab the portal revealer and buyable portals. The school bus uses a different portal to the families car.

If it's game wide it sounds more like a mod conflict, did you add anything recently?

As to starving, you can always buy a new fridge, however for a serous mod conflict you may need to do a search and fix it.

Mootilda's LotAdjuster (http://www.modthesims.info/download.php?t=384656) will reset all portals unless you 'tick' the Place Portals Manually option in the advanced options.
However I'm quite sure your issue is caused by bad or incompatible mod(s) and has nothing to do with portals.

Well, I'd agree, however, when I go back to my previous neighborhood, everything is fine, so if it was a mod issue, it would probably affect all neighborhoods, not just the one I'd not opened before, right? I think I'll go back to my old neighborhood, and leave this new one alone. Thanks for giving my problem your thoughts.

A 'stuck' travel controller would give the symptoms you describe, sims can go to work or school (because they don't actually leave the lot) but ownable cars and travel phone calls 'see' the existing travel controller and fail. I've never heard a travel controller continuing to exist after use or if it is possible to become stuck.
My 'Lot Cleaner' will take care of that or any similar problem.
CJH_LotCleaner.zip (44kb) https://app.box.com/s/zqpm2wwdcmryzdv096rkl4asx0naby7s