Since you have all been exploring Barcelona, here is some food for thought about automobile traffic and contemporary urban planning—for those of you interested in this sort of topic. If you are wandering the streets, you might try to find one of the proposed “superblock” (“superille”) sites in districts such as Eixample, Gràcia, and elsewhere. See the video below for more information.
The main recent superblock experiment, just finished in late 2016, which is currently getting a fair amount of attention—both praise and criticism—is in El Poblenou, to the east of the Citadel Park area. Here is positive piece in The Guardian, “Superblocks to the rescue,” from 2016. And here is one from early 2017 in Reuters, “Can Barcelona ‘superblocks’ cut traffic and clean up city air?,” that strikes a less optimistic outlook.
Feel free to dash off some thoughts about these projects.