The website of the Secretaria de Turismo de Rio Grande do Sul (the tourism authority for the state of Rio Grande do Sul) contains a section where users can download road maps. The download link is here and the maps are available in jpeg and pdf format.
As usual in the case of tourist information in Brazil, the page is in Portuguese only. Brazil needs to get their act together when it comes to travel information in languages other than Portuguese if it ever wants to increase the scarce number of foreign tourists that visit the country.
a handy tourist map of São Paulo
Google’s Street View has landed in Brazil
GoogleMaps on the Brazil Travel Blog
searching Brazilian addresses with GoogleMaps
the Brazil Travel Blog, geolocated