São Luís is a city in Maranhão, Brazil. It's historic center is a well-preserved UNESCO World Heritage Site, and it boasts some very nice beaches.
West towards Barreirinhas, Jericoacoara, Fortaleza
You need to take a bus out of the city into Rosario for better traffic going west.
You can take bus 066 from the historic center terminal (platform 2) to the Rodoviária stop. Ask the bus driver to let you know when to get off. Rodoviária is a huge bus station, but the public bus stop for it is just a normal street side stop, so don't miss it. It takes close to an hour in public transportation to get to Rodoviária from the historic center, so plan accordingly.
When in the Rodoviária station, you can use the company Cisne Branco to catch a bus to Rosario for R$ 11,00. Buses leave roughly every 2-3 hours. They have a good website for checking the schedules.
When you arrive in the Rosario bus station, it's a 6-700 meter walk a few blocks to the motorway, and the block before the bridge is a good spot to stand.