I was just watching an episode of Poroit, and they made a big deal about a new investigation. It was a map of London, and they had little model cars set on it. The cars would radio in their location, and people would move the models around to coordinate their movements. Was it just a literary device, or a real thing?
I don’t know but its easy to see why they might. Before police had cars and radios, they had a callbox system for dispatching, patrol reports, alarms, etc. Those boxes were represented on maps and I don’t doubt they added little model cars to show reported position on the maps as police got behind the wheel.
I would hazard a guess that police cars (once they had radios) were simply assigned their area of the precinct to patrol. Easier…
Considering how fast cars move, the “cars on a map” idea would not likely be a regular thing.