Each driver gets their own Driver ID.  When you set up your service plan, you will enter one Driver ID per Serial #.  

To set up additional drivers:

Go to connect.randmcnally.com and log in using the account information included in the “Activation” email you received when you purchased your service plan.

To add a driver, go to the Management tab on the Connect web portal toolbar. Click Drivers, Add Driver, input the information requested, and press Submit.

When you log out of the device, the second driver can use his/hers unique Driver ID to log in after, which will keep both of your logs accurate and separate from one another.