It looks like I can from andorradirectbus.es. Has anyone taken this busline before? Also, do you have to buy tickets online or can we just show up and purcahse tickets at Barcelona Sants? We aren't 100% sure of the day or time we would like to leave.

I am traveling to Andorra from Barcelona on Feb 12, 2013. I have never driven on icy/snowy roads. Do you think it is dangerous? Is it necessary to have special tires?

What ever possessed you to make this choice?..I am an experienced winter and mountain driver with many,many years under my belt. I wouldn't take this on if there was any other way at all. cars rented in Barcelona won't have snow tires and you may need chains which they definitely won't have. Try to make a change of destination or go by train/bus.

Just saw this Suzpessoa. Sorry I didn't respond to you earlier. Did you drive or bus it? We're going again in May and we'll be busing it. So much easier I think.

I actually made this trip a few days ago and thought I would give an update.
There are only two bus services that run from Barcelona to Andorra as of three days ago - Direct Bus and Novatel.
When I got to the airport I opted for Novatel. It's a small, older bus that sits 16 people. It took exactly 2.5 hours to get from Terminal 2 to the bus top in La Vella, which left me pleasantly surprised. It was 54 Euro for a round trip and you pay right on the bus.
I was thinking about staying overnight but after looking around for 5 hours, I needed to get out of there. Unfortunately I read the departure times wrong as I thought there were buses leaving at 6 PM and 8PM. When I showed up at 5 for the 6 O'clock bus the place was empty. I looked back at my schedule and said "yup, I'm a moron" - the last bus goes back to Barcelona at 3.
I walked to the Direct Bus office, which is right behind Novatel's, and I paid for a one way ticket back, which cost me 33 more Euro.
These buses make Novatel's look like Uncle Jed's jalopy. They are full sized, brand new buses. It took us three hours to get to the first stop, which is downtown Barcelona. 20 minutes later we rolled in to Terminal 2.To be fair, we didn't go to the downtown stop or Terminal 1 on the trip to Andorra.
If you want a faster ride go with Novatel, if you want a wider range of departure times and a nicer bus, go with Direct Bus.

Gillis.. you have been asking questions for several years.. and I would LOVE to see a trip report of what worked for you as a young family. I hope you find the time to do so as I am sure you have a lot of insight for others to take advantage of.

Yes, a trip report or two is definitely on my list of things to do. My head is hanging in shame. My husband always teases me for always taking, taking, taking from Fodors, but never leaving anything for others to take. Now I feel REALLY convicted and will try extra hard to make it happen for you guys! Thanks for the encouragement/kick in the butt lincasanova.