@Ghost. Motorcycles only display a number plate to the rear. So its speed is detected and then recorder as it approaches the van on the first rear camera. As the bike passes to the side of the van, a second side camera captures the image of the bike. Then a forward facing camera on the van picks up the image of the number plate. The cameras provide continuity of evidence from the moment the speeding offence is detected to the point where a bikes number plate can be read.
