See how adaptive signal controls can impact environment positively

Wed, 2018-07-04 11:21 -- SCC India Staff

Traffic congestion is one of the more frustrating—and seemingly unavoidable—parts of urban living. Gridlock can have a huge impact on the quality of life for city dwellers, not only in terms of time spent commuting, but also regarding pollution and emissions. Unfortunately, city traffic is likely only going to get worse: According to the United Nations, 68% of the world’s population will live in urban areas by 2050, up from 55% today. That means as many as 2.5 billion people will be migrating to cities.

The Delhi government came in association with PTV Group to test the effects of its technologies on traffic congestion in the city. Delhi is projected to be the most populous city in the world by 2028 and has an urgent need for traffic optimization. PTV leveraged its PTV Balance and PTV Epics solutions along 1.3 miles of Delhi’s Lodhi Road, which had six signalized intersections and three lanes of traffic travelling in each direction.

How it works
At the heart of this simulation are the concepts of signal optimization and signal coordination. Signal coordination is used to create what PTV calls a “continuous green wave,” allowing vehicles to travel seamlessly along a route thanks to a stream of coordinated green lights. PTV Balance is designed to synchronize green lights in the peak direction of travel. When implemented, vehicles headed in that peak direction stop at few intersections, cutting down on their travel time, fuel consumption and emissions.

Signal optimization through PTV Epics, meanwhile, focuses on improving the traffic at a single intersection. It considers the volume of traffic approaching from different directions and alters the light cycle to minimize the total delay all vehicles experience. PTV Epics optimizes the timing of traffic signals by estimating traffic conditions 100 seconds into the future with the help of real-time data. It can then lengthen or shorten green lights or eliminate cycles altogether to improve the overall flow of traffic. Balance and Epics can work together in a combined system to create a traffic control plan that spans the entire network.

Benefits of traffic control
Without Balance and Epics, PTV found that traffic along Lodhi Road during peak hours had an average speed of 11.5 mph and an average delay of 269 seconds. But with Balance and Epics running in the simulation, weighted travel times decreased by 26% while the speed of vehicles in the network increased by 27%. Additionally, the queue length at three of the six intersections was cut in half and delays along the network were reduced by 30%.

Should adaptive signal controls be implemented across Delhi, the estimated economic impact would reach $33 million. The environmental effects of smarter traffic control are also notable. In Delhi, the better flow of traffic that would result from adaptive signal control was estimated to reduce pollution levels by between 10% and 15%. Vehicles experience reduced fuel consumption and emissions due to fewer stops and shorter idle times at traffic lights.

Achieving the ultimate traffic optimization
The initial proof of concept was a success, but there’s always room for bigger and better benefits. That’s where Current, powered by GE, comes in. The partnership between PTV Group and Current by GE can further enhance smart city technology. Current’s CityIQ nodes can collect sensor data related to parking and transportation, including both vehicle and pedestrian traffic. Tools such as PTV Optima, which offers model-based real-time predictive traffic and incidence management, can take that data and translate it into actionable insights for customized traffic management solutions.

Today, most cities are using adaptive signal control based on the vehicle queue at the intersection without the intelligence of the traffic flow in the context of the entire urban area. This approach is a reactive solution that delivers limited improvements to the overall traffic flow.

By integrating the real-time CityIQ traffic data, PTV Optima offers precise, real-time and predictive traffic modeling for the entire network and produces reliable forecasts for up to next 60 minutes in 5 to 15-minute intervals. Traffic engineers can make informed decisions by simulating various scenarios with the real-time traffic data. Within a couple of minutes, a precise action can be taken based on the simulation results. Furthermore, the full integration of PTV Balance and the real-time traffic predictive intelligence from Optima enables the traffic signal control to achieve the ultimate optimization in the context of the entire urban area.

Less traffic congestion, reduced emissions and more economic development are sure to make cities better places to live. That will be much needed in the future when such a large percentage of the population resides in urban areas.