faster, they searched for an algorithm that requires less calculations – and they found one, as every user of the route planner can attest. Taxi to the Train Station, Plane to Rome The basic principle works, so now Bast and her assistants have turned their attention to the fine tuning. Their aim is to make route planning even more comfortable, more individual, and above all more realistic. Traffic jams and changes in public transportation schedules have a direct impact on trip duration and will thus be shown to the user. In addition, users will be able to integrate personal preferences like “not the quickest route but the one with the best scenery” into their search at the simple click of a button. However, the biggest challenge at the moment is multimodality. The researchers want to enable the user to freely combine different modes of transportation on their preferred route from A to B: a short walk, a train ride, and then the rest by car, or by taxi to the bus station in Freiburg at the start of a trip, from there by bus to EuroAirport Basel–Mulhouse– Freiburg, then by plane to Italy, and finally by train to the city center in Rome. How long would this trip last, when everything is taken into account? If Bast has her way, soon everyone will be able to find out themselves on Google Maps. But this idea can only succeed if all of the companies whose data Google Maps wants to use cooperate: airlines, local transportation authorities, railroad companies. In the USA, route planning of this kind with public transportation already works perfectly. The inhabitants of New York see how long they will be likely to spend in a traffic jam when they take their usual trip by taxi or bus from work to their home – and also whether the subway would be a better alternative or not. “In Germany, compa- nies like Deutsche Bahn and the regional trans- portation authorities aren’t nearly as generous with their data. That is still quite a problem,” says Bast. And so, she has to spend a lot of time per- suading the responsible protagonists from the private and public sector alongside her teaching duties and her research. At some point, however, the computer scientist is certain that the route planner will also function individually in Germany. “We log in. The route planner recognizes us and knows exactly how we like to travel – for instance that we prefer routes we can cover exclusively by public transportation and by bicycle, or that we like to travel from start to finish by car.” Such practical relevance is one of the things Bast likes about computer science. She studied mathematics and computer science in Saar- brücken. She soon found mathematics too dry and the presentation of computer science, which “It’s amazing to see all the useful things you can do by programming.” The quickest route or the one with the best scenery? Requests to route planners will take into account personal preferences. Photos: Matthias Buehne, Miredi (both Fotolia) 22