Phones (carplay / android auto) have replaced this. Google maps can show a much better picture of the current traffic conditions than a radio broadcast.
That's great when you never leave a 10 square mile bubble in the Bay Area.
There's a > 40 mile stretch of state route 542 (mt baker highway) in WA where there is no cell signal. Zip. Nada. No matter the carrier. And this road can carry nasty rapidly changing weather conditions in the winter. Your iPhone 26 will continue to proudly display "No Service." So, no, it has not replaced this.
iPhone 14 has satellite connectivity for emergencies, other handset makers are doing this too. in 10 years the picture will look much different, and i doubt any phone will ever have truly “no service” again.
T-mobile's claim is that by 2024 their customers will get emergency satellite connectivity on their existing handsets, even cheap $200 ones. They might need to be new $200 handsets in order to get the software support, but the hardware support is supposedly there already. The specific language T-mobile uses is the "vast majority of smartphones already on T‑Mobile’s network" which sure sounds like it includes $200 phones. With the help of Starlink, T-mobile is going to put cellphone towers in space, pointed down, and your existing cellphone will be able to pick up the signal and the satellites will be sensitive enough to hear the cellphone's transmissions.
T-mobile's service will be limited to various forms of texting and possibly also Twitter, which is used by many emergency departments to broadcast information, which is slightly different than the iPhone's offering of dire emergency service coverage. Still doesn't replace AM radio use cases though.
Satellite connectivity for emergencies will be just that, for emergencies. Technology will have to progress greatly (which, 10 years could do it) before "for emergencies" will include "you get data connectivity to tell you details of the road conditions" like you're imagining. In the interim, AM radios are still necessary.
Google insisted on showing roads continuing to be closed well after e.g. CalTrans issued a statement otherwise and reopened them, after the last bout of winter storms in early March.
The response time to displaying or ending closures related to wrecks on less well traveled roads is abysmal as well.
