Project overview:
Improve traffic efficiency and traffic flow quality
Reduce the number of stops and the amount of acceleration and braking
Increase travel comfort
Lower pollutant and noise emissions
 

Project partners:
City of Frankfurt/Main, Strassenverkehrsamt 36.53 (department for transport)
GEVAS software GmbH
AS+P Albert Speer + Partner GmbH
PROPROJEKT Planungsmanagement & Projektberatung GmbH
 

Project duration: May 2019 to March 2021

The “Green wave app for cyclists and drivers” project is subsidised by the German Federal Ministry of Transport and Digital Infrastructure (BMVI) as part of “Saubere Luft 2017 – 2020”, its immediate action programme for clean air.

Less stopping and more going: With the green wave app Traffic Pilot, drivers’ and cyclists’ smartphones will be able to tell them what speed to go to reach the next set of lights while they are green. This will make travelling in Frankfurt/Main an even more convenient and attractive prospect for cyclists. By stabilising the flow of traffic and minimising start-up and acceleration procedures, the initiative is also expected to lower the pollutant and noise emissions of cars. At traffic lights, the green wave app will even display a countdown until the red light changes if the driver was unable to optimise his or her speed.

For the green wave app to work, it requires an extremely accurate, reliable prediction of the expected colour of the traffic light which the driver is approaching. It is relatively easy to predict when traffic lights with fixed cycles will change as the lights in the individual aspect groups of a junction display each light at a defined second in every cycle. 
Modern traffic lights which operate on the basis of traffic change regardless of the defined seconds in a cycle. Instead, green lights can be extended or shortened and phases can be exchanged or omitted. As this depends on the volume of traffic as measured by detectors or on buses and trams which synchronise with the traffic light control unit, it is more difficult to predict what colour the light will be. All data from the traffic lights with no fixed cycle times are compiled by the integrated traffic control centre of Frankfurt/Main. In the project entitled “City-wide cycle time forecast” (an element of Frankfurt’s strategy to reduce NOx emissions), a web-based tool has been developed which can generate a cycle time forecast almost in real time on the basis of data from the integrated traffic control centre. The reliability of the forecast is also indicated by the colour in which it is displayed in the green wave app. 

The cycle time forecast is already available for pilot areas in Frankfurt/Main and will be tested by a selected group of users in spring and summer 2020. It is set to be evaluated after the summer holidays in 2020 and the pilot area expanded to cover all traffic lights connected to the integrated traffic control centre. If the pilot phase is successful, the green wave app will be made available to the public.