Unable to answer "What is the weight limit here?" for https://osm.org/way/1003658960 via StreetComplete 32.1:

No vehicles are allowed to cross the bridge.
On the main road, before turning to Rua da Igreja/Rua da Ponte Romana, there's a 'Trânsito Proibido' or 'No Vehicles' prohibitory sign with a complementary sign below indicating "na ponte medieval".

Attached photo(s):
https://westnordost.de/p/103539.jpg