Union City
Overzealous restrictions.
Union City has several marked truck routes.
Union City has a sprawling industrial district in between its long-united parts, the old towns of Alvarado (by the Bay) and Decoto (near the hills). This centers around the aptly named Central Avenue. Also, there is a large shopping center just west of 880, and two smaller ones in Decoto.
The city's marked truck routes 'cover' general access to these areas, but getting to many specific destinations will require a truck to go off-route.
The official city route map is pretty clear.