Can't get voice directions when using Maps in my Bluetooth enabled car

My iPhone 8 is paired with my car Bluetooth and the phone works through the car speakers just fine. However, when I try to get directions from either Maps or Google Maps, the route appears on the phone screen but I get no voice directions. This happened in my current car and with my former car so I figure it must be an iPhone 8 setting. I don't get voice directions either through the phone or through the car speakers.

HELP!