Either purpose built product or a mobile app.
I’d like one that takes into account your weight height etc.
Thats helps with parking & fuel.
Maybe thats ok for car as well, with speed camera warnings, but thats not essential.
I’ve got a tom Tom 6250, it’s never led me wrong, has all the vehicle variable inputs you’d need, and lifetime traffic updates, which I think is invaluable.
Other folk will recommend app-based products, but I’ve always preferred a stand-alone product, not least of all these days because as it does not involve using a mobile phone at all, it will attract less negative attention from the authorities.
And you’re not likely to be tempted to hold it in your hand like you might do with a mobile - which is all you need to be doing these days to get the CU80 code on your licence and all the other “good news” that goes with that.
I must say I’m impressed with the phone based app RoadLords. Running it side by side with the built in TomTom in my new Actros it was Road lords not Tom Tom that knew the M4 was closed today, and also knew the way from the dual carriageway to the industrial estate that didn’t involve going through a housing estate.
In my car I use CoPilot. They have a truck version which is similar but it is subscription (£80/year). Very good piece of software. Works offline and has traffic.