Hitchhiking was popular on interstates from the 60's through the 80's. The on-ramp was the platform where adventures began, standing by the entrance, thumb or sign in hand.

Today there are fliers standing by the exit ramps, holding signs for something else. Drivers passing, wondering what their stories are. Where are they going?

Roadside wildflowers
An affliction of weeds
or
A display of flowers?