Toll in Austria?

Do foreigners have to pay toll on the Austrian highways and do the have to pay it in advance or at tollgates on the road?
Can you have a vignette on the car that shows you have paid??

There are almost no tollgates in Austria. You need to have a sticker on the windshield as soon as you enter an Austrian highway this includes crossing the border on a highway. Only exception is small piece of highway at the German/Austrian border near Kiefersfelden/Kufstein.
Many service stations near the border also in the neighbouring countries sell them. There are 10 days stickers, 2 month stickers and year stickers at different prices. Fines are expensive if you don't have it.
If you rent a car in Austria it should have the sticker anyway if you plan to use a car you rented elsewhere ask the company if they have cars with the sticker.
Nevertheless additional toll (at tollgates) is asked for certain routes crossing the Alps (Brenner pass, Tauerntunnel, Arlberg Tunnel and some more). To avoid those you can leave the highway and use the regular street which are free but it will take a lot more time.

There is no toolgates on the Austrian highways. Everyone must buy a vignette and stick it on the windshield.
If you don't be prepeared to pay some serious amount of euros.

You can get a vignette ticket easily in any gas station. For your information, a ticket valid for 10 days costs about 7.6 euro.

Dear Hanya
Sorry , I dont know anything about it.
I can help you about Iran.