ProMods

In ETS2.

Any recommendations for an hour that contains some larger cities with several companies, so I can drive around delivering goods within the same one or two cities, having to deal more with traffic and potentially small roads, compared to just driving out on the highways?

You could try the Mainz area in Germany.

Apart from Mainz which is probably the most concentrated area, I'd say London area - Croydon, Portsmouth, Felixstowe all within a nice short range.

Another is Brno - close to Jihlava, Bielsko-Biala, Kraków and Ostrava.

Thank you both for your tips.
I already tried Mainz and it's a nice area to drive in