All supermarkets, pharmacies and hardware stores I've recently visited have erected plastic shields to protect their workers. But one area I've seen no protection for are drive-thru windows. All shift, the worker in the window gets quite close to customers, as they must hand them their orders.
In the UK, Redditor samanthavstheworld captured this footage of a drive-thru with a better idea:
Although you can't see it in the video, "there is a bumper raised thing on the road between the window and the cars," she writes, placing the cars at the appropriate distance from the window.
Also note that this is in the UK, where pickup trucks are virtually nonexistent and SUV uptake is not as pronounced as in the 'States. That's why the box is designed to lower to car height.
I like the design. It's simple, mechanical as opposed to electronic, and doesn't appear terribly difficult or expensive to construct.