Internet of Things (IoT) can help transport authorities to address the challenge of road traffic air pollution. The extent to which it can help varies across the different measures and solutions adopted. To some it is fundamental, to others it improves a solution that could function without IoT. The main shorter-term approaches to reducing traffic pollution are reducing vehicle usage via green modal shift, vehicle bans, telecommuting and trip-chaining; making vehicles cleaner, e.g. improved air filtering and electric vehicles; optimizing driver and vehicle performance; reducing congestion; smoothing traffic flow; and reducing exposure, e.g. by moving pedestrians away from heavy traffic or vice versa. Longer-term measures included better urban planning. An emerging area of research, development, and demonstrations in IoT and transport is the use of Vehicle-to-Infrastructure communications to reduce congestion and emissions. A great example of a large-scale distributed network of real-time air quality IoT sensors is the Newcastle Urban Observatory.