We asked TTC about this when we booked them because we have a 20 month old and a 4 yr old(who is about 40 lbs, and in a booster seat at home). They said they do provide one(and only one) car seat if you request it. Also, they told us that by law, children dont need to be in a car seat if they are riding on public transportation, and that is what TTC is considered. I would think taxis would be considered the same thing, but I dont know about that for sure. You might want to check that out if you are really stuck. Good Luck!