Students at my university in Berlin need to cross a busy road to travel between campus areas, which meant jaywalking or a long trip to a crossing with traffic lights down the road. A steady stream of students late to their next class sprinting across a six lane road is not great.

At some point students started painting their own crosswalk, which would be removed again and again by authorities, until the city eventually got the hint and installed a permanent crosswalk with a traffic light and a pedestrian island.

Sometimes the way to get something is fixed is by demonstrating the fix.