Is there a fee or any kind of charge for crossing the Czech Republic border - into or out of the country? And also, is there any fee for using the highways/main roads in the Czech Republic? We have tried to research this online but keep seeing conflicting information. This may just be associated with specific car rental companies but we are not sure. Thanks!
Jeannine, There is never a fee for crossing a border in Europe. Such a thing would probably be a breach of the EU freedom of movement, charging EU citizens for travelling within the EU. The Czech Republic is a member of both the EU and the Schengen area, as are all the countries around it. So there are no permanent border checkpoints going into or out of the country, just road signs. Though you might find some temporary police checks because of the current refugee situation.
Motorways (Autobahns) in the Czech Republic are called dálnice (abbreviation D) and do not have tolls.
There is a charge for using motorways in the Czech republic, have a look at this link it explains all, just scroll down the page a bit.
http://livingprague.com/driving.htm
There are no tolls for driving the highways in the Czech Republic but you do need a vignette which can be purchased near the border crossing into the country. There are clearly marked vendors that sell these and they are not expensive. Make certain to stop and buy one because the fines are stiff for not having it affixed to your windscreen. If you rent the car in the Czech Republic it will already be on the car, otherwise, you will need to stop and buy one.
That said, the motorways in the Czech Republic are excellent. They are rapidly expanding them but they aren't all complete yet. We took one on a regular basis this past summer and there was a place where you had to turn off the road to a smaller road because the new motorway ended at a wheat field! There will be a ring road around the outskirts of Prague when they are finished as well as a network of roadways around the country, many of which are already in place.
Everything what you need for driving in C.R. was already answered by my predecessors. Especially website provided by Unclegus is very useful. Read it all. Motorways (or freeways) are indeed good or fairly good, well, with little exaggeration we can say excellent. With at least one exception and that's D1 (Prague to Brno). In disrepair, a lot of construction, miserable experience to drive it.
Do make sure your car rental company knows you are taking the car into the Czech Republic. They often restrict which models are allowed to do this.