Traffic is among the largest contributors of air pollution in our cities, and urban populations are still on the rise. More people means more cars and more traffic congestion on roads, so improving transportation networks is a great way to improve air quality. Less time spent in cars means less exhaust, cleaner air, healthier citizens and a more sustainable city.

For many reasons, the path to becoming a "smart city" begins with smarter streets. Not only can smarter streets help us use our existing transportation infrastructure more efficiently, get to work faster and decrease pollution, but the infrastructure improvements cities are already making will prepare them for future initiatives that make other parts of city life better too. Let's walk through the process of creating intelligent streets and how smart streets make smarter, more sustainable cities.

Traffic

Traffic is a common denominator of city life. Whether you walk, bike, drive, or take public transit, everyone knows the frustration of waiting for lights to change  – only to inch forward in a line of cars. The solution to this universal problem isn't building more roads with more lanes -- that's been proven. Instead, what cities need to do is make better use of the infrastructure they already have; our city streets need to get smarter.

Creating smarter streets starts with better intersection control. Odds are good that in your city, street light timing is only changed once every few years and is done by a city worker going to a traffic cabinet to adjust timing. In our current age of "connected everything," this is not just unacceptable, it's a bit sad, too.

Connecting these cabinets to the Internet lets traffic engineers monitor the flow of traffic from one central location. Take the power of an Internet connection one step further, and these engineers can program traffic light cycles in real-time, extending a green to clear a backup or perhaps turning a left-only signal off sooner to get traffic flowing in the opposing lane.

Sustainable Mobility

The end result of smarter intersections is not just a less stressful commute. Connecting a city's traffic network and giving traffic engineers the power to continually optimize will reveal new efficiencies for transportation, meaning a more diverse mixture of mobility options available to city-dwellers.

Consider the example of the urban bus route. Today, you pay perhaps $3 a day to sit on a bus in traffic. Is it more efficient to carry 50 people in one vehicle than in 50 vehicles? Yes. But is the current practice sustainable? No. In many cities, buses are underutilized and deal with the same traffic as everyone else on the road.

Many cities have added Bus Rapid Transit lanes – BRT – to their city cores to address this problem. BRT lanes allow buses to travel more freely through traffic, reducing time spent on the road and hopefully the ratio of particulate emissions to passengers. But buses in BRT lanes can still get stuck at red lights. What good is a dedicated lane if you're still hitting every red?

Smarter streets could make BRT much more effective by connecting sensors at intersections to buses. As a bus begins its route, the connected traffic network can monitor its progress, and change the timing of traffic lights to give the bus as many greens as possible.

Mixed mobility doesn't end with buses, either. Optimized traffic makes streets more pedestrian-friendly and makes it easier for bicyclists to commute safely and quickly. These are the aftereffects of smoother traffic flows through the city: more people choosing sustainable and efficient ways to get from A-to-B, which means even less traffic congestion and cleaner air.

Domino Effect

Yes, smarter intersections mean less congested roads and safer routes for drivers, cyclists, and pedestrians. Smarter streets also help create more (and more efficient) mobility options, further reducing the number of cars on the road. But the same sensors found at  intersections can also help cities increase the efficiency of other services in need of a sustainability overhaul.

Energy delivery, particularly to streetlights, is a massive expense for cities, and electricity generation is another contributor to pollution. Smart streetlights, which you can already find in cities around the world, could use open data shared by sensors at intersections to automatically dim when traffic is low, reducing energy usage without inconveniencing residents.

An interesting example of how complex city systems can complement each other actually comes from trash cans you've seen on city streets for years. The popular solar-powered, connected trash can/compactor combo already reports to waste management teams or private companies when it is full. Combined with data collected by traffic light sensors, trash cans at smart intersections could do more than report a full can, they could help waste management providers plan the fastest (and thereby most efficient) route through cities, reducing the number of hours each trash truck is on the road.

Today, there's no single right way to create a sustainable city. Fortunately, the tools and expertise needed to create smarter cities exist, and many cities are already implementing them to great effect. But because cities are often lacking both budget and talent to implement sustainable solutions on a large scale, they must first focus on creating and enabling efficiencies in their most problematic systems. Traffic networks are among the largest and least efficient systems in our cities today. By making improvements one intersection at a time, cities can address citizens' pain points while making transportation (and later, other services) more efficient and more sustainable.

Kurtis McBride is CEO and co-founder of Miovision, a smart traffic company.