Try Waze app. If you avoid the highway that you want to avoid, Waze will update your route and it is free. This app is free.
Not that familiar with Dallas. Check your Google maps for side roads. There are some major streets that have good traffic flow. Skillman, Abrams, Greenville Ave. and Northwest Highway come to mind. They are good for avoiding Central Expressway/75. Google maps has always been right on target for avoiding congested roadways.
Thanks! Your answer is awaiting moderation.