greenway is an innovative navigation system which significantly reduces co2 emissions of cars and therefore protects the environment. the system orchestrates the traffic through a distributed routing algorithm in an optimal way. ordinary navigation systems divert traffic jams onto smaller streets after they occurred, whereas greenway actively prevents traffic jams. this is possible because greenway reserves time slots for cars on the streets. with this technique, greenway knows the position of participating cars for any given point in time, including the future.

the heart of the system is an optimized graph traversal algorithm that calculates shortest paths in a matter of milliseconds. the implementation includes many heuristics in order to reduce the complexity of calculating a route to nearly linear time. the greenway traffic simulation software simulates various traffic flow scenarios in different congested areas. the result of the simulations is traffic flow that is twice as fast.

furthermore, a windows phone application is used as a front-end for customers. the greenway application is connected to the routing service, which is hosted using the windows azure cloud. therefore it dynamically shows the optimal route to the customer.

generally, the greenway service scales with the number of customers. through switching computer instances on and off, a huge number of users can be processed, whilst costs for the technical infrastructure only incurred when the infrastructure is in use.