Nope, no counter form needed:
Go to avis.com->Customer Service (top right corner)->FAQs->USA->Reservations->Rental Policies, Terms & Conditions:
The following individuals, if 25 years of age or older and in possession of a valid driver's license, may drive the car with the renter's prior permission and are exempt from Additional Driver fees:
Renter's employer (while on company business);
Renter's fellow employee (while on company business
Renter's spouse or life partner.
Disabled renters who have completed the non-licensed renter form
A maximum of 2 additional drivers can complete an additional driver form* for a rental. To save time, you can print out this form, complete and bring it with you to the counter. Additional drivers who can drive the vehicle with the renter's permission (see Exceptions above) are not included in this requirement.