Width of slab integral with beam

Hi I'm an out of the closet bridge engineer , my question is why aren't you using AASHTO, since it's the bridge design code?ACI 318-19 6.3.2.1 is for concrete T beams, although new concrete T beam bridges are few and far between these days. ACI Chapter 8 is for two-way slabs, which is a common building system but uncommon for bridges.

Because I'm studying for the SE exam not designing a bridge.

Doesn’t the SE have a bridge component as an option? Why identify yourself as a bridge engineer if you’re trying to understand building design?

SE exam has lateral and vertical breadth components which mean everyone needs to study ACI, AISC, TMS, NDS and AASHTO. There are also vertical and lateral depth components and yes I'll be taking the bridge option for the depth components. For the breadth components I had a question about ACI so I came here.

I guess since it was my first post on this forum and since it might appear to be a bit of a basic question to someone who uses ACI day to day I thought I'd introduce why I was asking the question - the reason I came here is because I'm a bridge engineer so I don't normally use ACI but in the near future I'll have to answer a bunch of questions about ACI.

The whole SE system would be much better if you could pick only the parts you're interested in but I don't make the rules. If you want to sign/seal bridge plans in WA state you better learn how to design a masonry shear wall and know where to look up the withdrawal strength of a nail!