The sensors pick up the vehicle’s “thermal signature” which means the hot engine and they claim it would detect a motorcycle.
However, they may not be particularly useful for cyclists and the riders and drivers of the coming wave of cooler-running electric vehicles.
They also only alert vehicles approaching the stop signs, not other vehicles on the crossroads, not do they alert of vehicles on the crossroads.
While there is no substitute for staying alert, anything that could make riding safer without costing a fortune should be welcomed, especially in rural areas where these regular stop signs may not be lit.
The solar power means they do not have to be connected to the grid, so they would be useful in rural and more remote areas.