Sorry, I just realized that there was a page 2 on the slow travel talk link of Ribeirasacra.
It seems that things may be better from July - unfortunately too late for us so my question remains.

Use ViaMichelin to plan your route and use the no tolls option.
http://bit.ly/portugalroute
As the pass only 3 days and you wish to travel further days then you can either purchase the 3 day pass for a second time or purchase a "ticket2 covering the specific journey.

You can drive from Lisbon to Porto on the A1 tollroad, where they still have manned tollbooths! So you can pay either in cash or with your credit card. It's an easy 300 km drive. We will be driving there again in 5 days. Can't wait.

The problem of the tollroads without tollbooths (electronic tolls) is mainly on the A22 in the Algarve.

The situation in the Algarve is fluid. There are a lot of challenges on the legality. You can always use the N125 to bypass the tolls.

I was just there in Feb and had issues finding out how to pay. I tried to pay at the airport. The rental company was no help. The post office was closed...so, I didn´t pay (just like the vast majority). The rental company had my credit card but so far no payment. I will be spending the summer there.

SloJan2, probably the previous renter paid your tolls. That is what happened to us when we were at the post office this afternoon to pay our tolls of 4th and 6th inst. The clerk told us there was also an unpaid amount (0,95 euro) of 3rd inst., half a day before we picked up the car and on a tollroad that we didn't drive. We paid because the amount was so small.

I intend to set my GPS for no tolls and see where that gets me.
This two weeks we have not set itinerary. We are just playing it by ear. So I will see.

Thanks Myriam, that is good news for Lisbon to Porto!
The A22 seems to be more of an issue - not taking the toll road would add a couple of hours to our trip I think, will have to have another look at that.

MyriamC, well, that's a bummer. I owe someone 6 Euros. Beats me why the PT just can't go to a vignette system like the Austrians and the Swiss.

We have been driving all over the north (are now in Obidos) for the past week. The tollroads are just fantastic. Hardly anyone drives them, so I don't mind to pay a fee to use them but the system of the electronic tolls is a pest for foreigners in a rental car. We also sometimes set our GPS on 'avoid tollroads' but not if we have to drive 600+ kms like we will at the end of our stay (from Tavira all the way back to Porto to catch our flight back home).
Well, tomorrow we'll be on the road again. To Evora this time, which we will do on the national roads (easily doable on a Sunday).

Myriam. I don't blame you for using toll roads when you have such a long distance.
It really cuts down on the travel time. But we intend to meander.

Sher, we are here for three whole weeks, and still feel we are rushing it. We're such slow travellers ...

Myriam, slow is good.

Myriam I think slow is good too.
I have been three times for two weeks each and there is still a lot we haven't enjoyed.
This year it is a family vacation so we are staying in one place. We have a car and plan to do some things but I guess I will just have to return again.
We haven't spent enough time around Porto yet for my taste.
Are you enjoying yourself?
We have done some parts, like the Alentejo coast, which some people don't get to. So I guess we are doing ok.

We haven't spent enough time in Porto, either. We were there for 5 days last year and will go back now at the end of this holiday for 2 more nights (2,5 days). Still too short but it is easily doable as a citytrip (we live in Belgium).
We are very much enjoying ourselves. We're just halfway and feel that we have seen so much already. First stop was Braga for 3 nights with sidetrips to Viana do Castelo and Guimarães ; second stop was Obidos for 3 nights with sidetrips to Tomar, Nazaré and Peniche. Third stop was Evora for 3 nights with a short sidetrip to Evoramonte and we drove the megalithic route. We are in the Algarve now (Tavira, it's our third time here and we feel it as our home away from home) and truly enjoyed our trip through the beautiful Alentejo countryside and the different serras. We have seen all the places in the Algarve as well as some of the inland, but there is still enough to do and see to keep us busy for the next ten days before driving back to Porto.

An update for anyone considering the A22 route. We stopped at a service station just inside the Spanish border which had a big poster in several languages basically outlining info we already knew but they did not sell any passes/vouchers. The lady told us that we could get what we needed at the 'frontier' near the police station - sure enough virtually as soon as we crossed into Portugal there was a police station on the right which was totally chaotic as far as parking was concerned because of a large amount of roadworks happening. We were waved away from the obvious parking by the policeman standing out front (outside police station where there were plenty of parks!) and joined a number of vehicles trying to find a place to park near the tiny booth containing the self serve toll passes.

People were very confused as to their options but we knew we were going to get the 3 day unlimited for 20 euro and the machine did have English options and was pretty easy to navigate. (make sure you have your registration number handy) I didn't see any option for buying a "point to point" option but we just decided that the 20 euro sounded ok for us.
Hope this helps someone!

The situation is changing.
http://algarvedailynews.com/news/6789-extra-staff-being-recruited-to-explain-tolls-to-foreign-drivers

The new system explained in the article is only good for foreign registered cars, not for rental cars with a Portuguese licence plate of which there are thousands on the road in the Algarve. Such a shame!

My 2 cents worth.
Extra staff to explain a system in use for several years. Why now?
Extra staff to explain the system, how? Like will they stop everyone driving along not understand the road signs and explain?

Another update - went into the Post Offce today to do the right thing and 'pre-pay' our trip from Porto to te airport on our last day. Apparently the toll is 0.50 euro cents. The lady in the post office informed me that there is no way for foreign registered vehicles to pay specifically this journey. The only option was a 10 euro pre paid fee.
Hopefully the Portuguese government will have better things to do than chase me in Australia for 0.50 euro cents! We're going to risk it.

They will not chase you back home. However if you do not pay you could get caught by the police in Portugal. Fines are instant and relatively high.

On our way from the Eastern Algarve to Porto we did everything we could to avoid the A22 (which is electronic toll only) because we would fly home the next day and there was no way to pay the toll (your passing needs 48 hours to show in their system). We managed to get to our hotel in Porto through 'normal' tollroads. Woohoo!
The next day we drove to the airport and - you won't believe this - all of a sudden that € sign on the road ... for 0,25 euro! So, we are now awaiting an invoice for 0,25 euro and a fine (that is what Europcar told us). To be continued ...

Myriam, have replied twice to this and posts not appearing??
Anyway, thanks for your enthusiasm and input on Portugal, probably included it in our itinerary partly on your posts!
LOVED Portugal.
We had to return our lease car to an industrial type area near, but not at, the airport and then they shuttled us to airport. Because of this I'm pretty sure we actually missed all electronic toll roads!
Hope things turn out fine ( no pun intended) with your experience.

In addition to the good information here about the toll roads in Portugal, it's
worthwhile to check out the 'slow travel' site. The moderator is based in north-west
Spain and has become something of an expert on the tolls. His section is hugely
popular and posts almost daily.

wfg463 That is me!
ozgirl fingers crossed or you...Glad you loved Portugal.
MyriamC toll+fine+ admin charges. We wait to hear back from you. It maybe be months it maybe a week before you receive the bill.

Appreciate the info here.

You know, for someone like me who is sitting here deciding on when/where to spend my precious holiday time, this certainly is a tick in the negative column for Portugal. I'm sure the good out weighs the bad but maybe it's just the thing to send me (and others) to another location.

Maybe I'll go to Barcelona . . .

. . . wait, I'm bound to get pickpocketed there.

These toll roads can be avoided...pickpockets are harder to avoid!
Don't let this put you off going to Portugal, just be armed with the information.

desculpe ribeirasacra! missed your postings here! please keep up the
terrific updates. I travel regularly to Lisbon (wife's family) and they are
invaluable.

muito obrigado!

Indy_dad, go to Portugal! It is beautiful, toll roads are a minor detail. One thing to be clear about there is that there are only a small number where this is a problem (with the electronic unmanned roads,) many are just your normal manned booths - a little research and you'll be fine. Enjoy!

After much research and information from ribeirasacra (thanks!) we ventured into Portugal from Spain onto Portugal A25, driving a rent car with Spanish plates. Before we got to the start of the electronic system, we began looking for signs about the electronic tolls. Nothing. It was Sunday so the post office was closed. In fact, everything along the way was shuttered and closed. We saw no signs indicating Via Verde or anything similar. We even parked, got out and searched for information. nada. Sooo -- we drove on, right under the electronic thingy and onward. I thought at any moment the police would stop us and impose a huge fine but luckily that didn't happen. In Coimbra, our first stop, our B&B hosts assured us that we could pay at the post office on Monday. No. We were told we couldn't pay after using the road because there was no way to access foreign license plate numbers, so it was "free." We were offered a 3-day pass for 20 euro or a 5-day pass for 10 euro but we could use neither because we wouldn't be on the electronic highway for several days. Thereafter, we avoided the electronic toll roads until we arrived in Lagos. When we were ready to leave that area, we went to yet another post office. After much discussion and even more time, it was finally determined that a 10 euro 5-day pass would get us out of Portugal and into Spain -- if we were leaving that day and would enter Spain the same day. Presumably, but not explained, if we were to be in Portugal a longer time, we would have to ?load? more money onto the card. Unsure the procedure, but no matter. We got our pass and swiftly made our way onto the A22 and over the Spanish border. We still technically owe for our jaunt along the A25 and have no clue if we'll get a bill someday. My advice to travelers with out-of-country license plates is to just avoid the electronic tolls when possible. And don't take advice from any well-meaning Portugese natives unless they work for the highway system or the post office. They understand only the system as it pertains to residents of Portugal -- at least that was true of all the ones who tried to help us. In retrospect, the electronic toll system is a royal pain, but not so much as to prevent me from going again. Portugal is a wonderful tourist destination.

Yes, Indy_dad, go to Portugal! It is a beautiful country, with wonderful people. Even a big fine for not being able to pay our 0.25 euro toll will not keep us from going back next year, and hopefully still this October.

Well, the good news is that if you are coming into Portugal on the A22 (from Seville), they have a great system set up. We drove through it on July 3. We saw the signs for foreigners, pulled over as indicated and the car was approached by a very nice young woman askin what language we spoke. Now, they just take a picture of your ca´r´s license plate, link it to your credit card and will charge your card automatically. It works on all non-traditional toll roads. Easy peasy. There were about 5 stalls to handle the cars expected during the tourist season. So, no more hopping to the post office for us.

For those checking this post, my recent trip to Portugal involved picking up a rental car in Porto at the Rua Antonio Bessa Leite downtown location. (I had traveled by bus from Lisbon to Porto, and spent some time in Porto before needing the car. Also didn't want to go to the airport to pick up the car as an electronic toll road is involved somewhere around the airport.) A week later I returned the car to the Lisbon airport. My drive south from Porto to Lisbon was via Coimbra, Obidos, Estremoz, and Evora, and I managed to avoid any electronic tolls. I came close where there was a short stint on the A17 when going between Coimbra to Obidos, but went through the outskirts of Leiria to avoid the electronic tolls. I did pay tolls throughout the drive at booths, but avoided the electronic tolls and the pesky procedure to pay them!

Europcar provided me with a list of the electronic toll roads (called SCUTS): A28, A4, A41, A42, A17, A25, A29, A22, A23 and A24.

The greatest help we had on the road - my friend's iPad2. While she didn't have access to the internet during the drive, she pulled up the daily route using wifi and the map app the night before. In the car she could access this route, enlarge it when needed, and a blue dot gave our car's specific location! To me, magic!!! Any wrong turn was quickly resolved by checking for the blue dot. Very helpful when navigating the outskirts of Leiria.

We had a great time in Portugal. Don't let the electronic tolls discourage you, especially since they can be avoided.

Slojan2, sounds like the system you encountered was perhaps what all the construction work we saw on June 15 was about?
Glad it worked well for you, it's obviously evolving daily!