If you are visiting Sines, chances are you are either coming from or going to Lisbon.
To do that, there is the auto-estrada A2 connecting to the IP8. These are both relatively fast highways. The problem therein is that you must pay tolls and do not see much along the way. In total, you'll have to pay about 10Eur in tolls.
I suggest that you take the extra ~30 minutes and take the scenic route. The N261 is a much more scenic route. Between Setubal and N261 is a ferry (11Eur). The slower road winds up taking about the same time because it is many kilometers shorter than taking the auto-estrada around the bay.
There are many kilometers of beaches and scenic views along the way. There are also a few random things like the Rice Museum near the town of Comporta.
Sines has the only leisure harbour / marina between
Setubal and Algarve, stopping place for pleasure boats in national or international
sea routes along our coast. It has a 230 place berth and is fitted out with
all the essential equipments to an exigent sailor.
not trying to miss led you, this transportation tip ain`t really a tip.
Trains does not stop here anymore,
but that was the only way, to show you the beautifull and (not) abandoned
old train station on my town. recently a huge and beautyfull garden surrounds the site. ( soon i´ll add some pics...