This information will assist you if you intend on hiring a car at the airport and driving up to Andorra. A rental car provides the added benefit of being able to get out and about whilst on your holiday, giving you more flexibility and being able to see more of the country, however it is worth bearing in mind where you will park the car and the potential cost of doing so.
When driving to Andorra it is very important to consider that you will be driving high up into the mountains, and hopefully there will be loads of snow! It is highly recommended that your car has snow tyres, but also that you carry snow chains. If you are renting a car from the airport, try to book these both in advance.
You can be stopped by the police and not allowed to continue if the weather is bad and you do not have winter tyres or snow chains so it is best to be prepared. The weather can change very quickly, and access to Andorra from France is up a very steep windy road so if the weather is bad you will most probably need chains. If there is lots of snow around, you will also find it very useful to have a shovel in your car so that you can dig yourself out, and some spare waterproof gloves and clothes so you can keep warm whilst doing so!
Winter tyres greatly increase your grip, and therefore your control, when driving in winter conditions. Often referred to as snow tyres, they are more effective than regular tyres even just when it is cold without any snow, so definately recommended for your car if you are driving in Andorra. Some people just add winter tyres to their drive wheels, although your car will be more balanced and less likely to skid if you fit them to each wheel. If you are renting a car you can usually add winter tyres as an optional extra, or if you are taking your own car you there are lots of options of where to buy them, whether you prefer to visit your local garage or you can order them online and even get fitting included with an online order.
You can identify winter tyes by looking for the snowflake symbol on the tyre wall, and when it snows heavily the police will check to make sure drivers have winter tyres fitted, if not you will then be required to either fit snow chains or to turn back. Even if you have winter tyres fitted you should still carry snow chains in your car for when there is heavy snow.
There are customs checkpoints at both the French and the Spanish borders. At the French side you should slow down, and stop if indicated, both on the way in and out of Andorra. The same applies to entering from Spain, however on the way back in to Spain it is compulsory to stop and open your boot. If stopped you will usually be asked if you have any alcohol or tobacco, so make sure you know the limits.
In Andorra there are no motorways, and the speed limits vary up to 90km/h, and are usually well signposted. You should also keep your eye out for signs indicating parking restrictions as if you are caught parking illegally you can be given an on-the-spot fine!