Wow, you're considering making Immersive Interiors for your suburbs? That... is dedication. I mean, even just considering the possibility shows that you are really invested in making your mod fantastic, since that extra work is not necessary for completing the mod in good form.
richardrocket, if you look through past posts you will see that Lady Olivia and Arthmoor believe that ICS is compatible with Roads and Bridges. The two mods alter non-overlapping areas.
Personally, I feel no particular eagerness to see extra bridges on the Imperial Isle. I mean, I won't object at all if they're added as a part of a worthy mod such as ICS, which does a lot to improve the surroundings of the IC and make it more integrated with its environment. Simply taken by themselves, though, I don't find bridges very attractive. The Imperial City
is meant to be a quasi-fortified, quasi-medieval city, and limited access to the Isle is really the strongest defense the city has. Big, stone walls surround the city - but no serious defenses around the wooden doors, alas. Which is to say: Lady Olivia, do your thing and don't feel pressured. Your readership is by no means united on the subject of bridges. I trust that you will put bridges where bridges belong.

Beautiful screenshots and good work! Thanks for your contribution to the modosphere.