What tests are being conducted to encourage residents to return public seating?

Answer: pay-to-sit

In Bat Yam, Israel, Vincent Wittenberg gained permission from the city to "replace existing public benches with benches that consist of individual seats," he wrote on his website. "The bench itself is a docking station: using a five Shekel coin one can release a seat and place it in a different spot. The deposit is returned when one brings the seat back."

And in Berlin, artist and designer Fabian Brunsing created public benches that require a (non-refundable) coin deposit. Upon inserting coins, metal spikes retreat into the bench, and when time is up, an alarm sounds to warn the person that those spikes are on their way back up: