Embark Studios seems interested in building out Speranza to be a walkable hub area.

In the world of ARC Raiders, Speranza is the underground city that humans live in when they’re not exploring and scavenging Topside. It’s also where players can store and retrieve their stash.
As it is, you have a bed to sleep in, traders to meet, and even some NPCs to talk to. But it could have been more.
Embark design director Virgil Watkins said this in an interview with PCGamesN:
I mean, we’ve 100% discussed it. I think it was like the first question asked when we started building the front end of the game, you know, ‘what would that experience be like?’ It always came down to time and scope for us.
…So yeah, it’s something we have discussed, and we’ll continue to discuss, and I think there’s definitely a good appetite on the team for it as well. It’s more about when the right moment to open that door is.
ARC Raiders’ unexpected success will allow Embark to build out Speranza to live up to their original ambition, if they wanted.
