Cities like Stockholm, Brisbane and Singapore have discovered that traffic is not just vehicles in a line, but a network of connections and units that can communicate with each other. These cities have all introduced intelligent solutions in their traffic-systems. Roadsigns, traffic signs, critical intersections, etc. communicates with each other and with the vehicles that people use, fx. by using intelligent sensors on cars. The result is an optimization of traffic flow and lower emissions in all three cities (fx smart traffic systems in Stockholm). The Copenhagen Wheel – the intelligent bike-wheel presented at COP15, which collects information about traffic, air pollution, etc. is also based on this ’Smart City’ idea.