Carol writes, “My daughter is taking her cat by car from New York City to Florida. What does she need to know to make this a smooth trip? Might a sedative be appropriate?”

Great questions, Carol, and ones that are frequently asked.
You hit on an important point. Sedatives are indicated for any pet who exhibits anxiety during travel.
Cat sedatives, like dog sedatives and people sedatives are prescription medications, so your daughter can get that from her veterinarian, or, if the kitty isn’t current with a doctor, an appointment can be made for an examination to be sure he’s healthy enough for the medicine, as well as the travel.
While there, he should be updated on a test for Feline Leukemia Virus (FeLV), and
Feline Immunodeficiency Virus (FIV) .
If those two results are negative he can have updated vaccines. It’s best to do this well before the trip so that full protection is achieved prior to departure. If these are his first vaccinations, boosters are needed. On the first visit he should also have a fecal flotation to test for intestinal parasites.
I have written a few pieces on my blog about travel. Here are the links: Pet Travel Safety Part 1 , Pet Travel Safety Part 2 , Pets Must Not Ride In Drivers’ Laps , Keeping Pet Travel Safe And Healthy .
Your daughter will want to be sure the kitty is in a secure cage or carrier and the cage should be firmly attached to the inside of the car with a seat belt and/or rope. Its door should be secured with easy-release wire ties to ensure its integrity in case of a crash while still making the door easy to open in case of emergency.
Acclimating him to car rides by taking short, then longer and longer rides prior to the trip will help make the trip easier, too. Start the trip on an empty stomach and feed him when she stops for the night. Water should be available at all times.
I think that will solve all of the problems!
See you next week, Dr. Randolph.