Impact assessment of autonomous DRT systems

The market entrance of shared autonomous vehicles (SAV) may have disruptive effects on current transport systems and may lead to their total transformation. For many small and medium-sized cities, a full replacement of public transport services by these systems seems to be possible. For a transport system operator, such a system requires a bigger fleet of vehicles than before, however, vehicles are less expensive and fewer staff is needed for the actual operation. In this paper, we are using a simulation-based approach to evaluate the service quality and operating cost of a demand responsive transit (DRT) system for the city of Cottbus (100 000 inhabitants), Germany. The simulation model used is based on an existing MATSim model of the region that depicts a typical work day. Results suggest, that the current public transport system may be replaced by a system of 300 to 400 DRT vehicles, depending on their operational mode. Compared to previous, schedule based public transport, passengers do not need to transfer, and their overall travel times may be reduced significantly. Results for the cost comparison are preliminary, but results suggest that an autonomous DRT system is not necessarily more expensive than the current public transport system

Towards a Testbed for Dynamic Vehicle Routing Algorithms

Since modern transport services are becoming more flexible, demand-responsive, and energy/cost efficient, there is a growing demand for large-scale microscopic simulation platforms in order to test sophisticated routing algorithms. Such platforms have to simulate in detail, not only the dynamically changing demand and supply of the relevant service, but also traffic flow and other relevant transport services. This paper presents the DVRP extension to the open-source MATSim simulator. The extension is designed to be highly general and customizable to simulate a wide range of dynamic rich vehicle routing problems. The extension allows plugging in of various algorithms that are responsible for continuous re-optimisation of routes in response to changes in the system. The DVRP extension has been used in many research and commercial projects dealing with simulation of electric and autonomous taxis, demand-responsive transport, personal rapid transport, free-floating car sharing and parking search

Electric Taxis in Berlin – Analysis of the Feasibility of a Large-Scale Transition

Battery operated electric vehicles (BEVs) offer the opportunity of running a zero-emission car fleet. However, due to their current range constraints, electric vehicle operations are mainly attractive for inner-city transport, such as the taxi business. This paper is bringing together facts and assumptions about Berlin’s taxi transport and the current conditions of BEVs in Germany to provide the scope of electrification. Firstly, the necessary amount of fast chargers is determined taking general constraints of Berlin’s taxi business into account. For charging, especially busy days during cold winter days will be critical. Furthermore, a pricing scheme for fast charger usage is introduced. Based on this, operating operation costs of a hybrid electric vehicle and a battery electric vehicle are compared. The authors conclude that BEV operation will only pay off if the vehicle’s battery life can be warranted over a long span or costs of electric energy in Germany drops

Should autonomous shared taxis replace buses? A simulation study

The introduction of shared autonomous vehicles (SAV) will likely reduce operation cost per vehicle and might thereby allow to enhance conventional public transit systems with numerous small SAVs offering exible ridesharing-like feeder services. These demand-responsive services could replace conventional bus lines limited by their fixed routes and their fixed schedules. This simulation study explores the potential of replacing conventional bus lines with shared autonomous vehicles in a suburban area of Berlin. Several scenarios with different fleet sizes and vehicle sizes are simulated using the multi agent transport simulation MATSim. The simulation suggests for all evaluated scenarios higher operating costs and only slight travel time savings in comparison to conventional buses. Door-to-door service allows for significant reductions in average walk time, but causes numerous detours which consume a high share of the time gained. A fleet of 150 SAVs with 4 seats each seemed appropriate for the simulated area with approximately 24 000 inhabitants

Proactive empty vehicle rebalancing for Demand Responsive Transport services

Worldwide, ridesharing business is steadily growing and has started to receive attention also by public transport operators. With future fleets of Autonomous Vehicles, new business models connecting schedule-based public transport and feeder fleets might become a feasible transport mode. However, such fleets require a good management to warrant a high level of service. One of the key aspects of this is proactive vehicle rebalancing based on the expected demand for trips. In this paper we model vehicle rebalancing as the Dynamic Transportation Problem. Results suggest that waiting times can be cut by around 30 % without increasing the overall vehicle miles travelled for a feeder fleet in rural Switzerland

Barrierefreie Taxis für Berlin: Bedarfsermittlung und Abschätzung der Flottengröße

Die Berliner Taxiflotte weist aktuell nur eine geringe Anzahl an barrierefreien Fahrzeugen auf, welche von RollstuhlfahrerInnen genutzt werden können, ohne den Rollstuhl zu verlassen. In diesem Kurzpapier wird anhand eines Simulationsmodells untersucht, wie viele Fahrzeuge der stadtweiten Taxiflotte mindestens barrierefrei zugänglich sein müssten. Dafür wird zunächst eine Abschätzung der Nachfrage vorgenommen und sodann die notwendige Flottengröße ermittelt. Die Ergebnisse zeigen auf, dass eine Flottengröße von 250 Fahrzeugen eine hinreichend gute Angebotsqualität liefern können

An Assignment-Based Approach to Efficient Real-Time City-Scale Taxi Dispatching

This study proposes and evaluates an efficient real-time taxi dispatching strategy that solves the linear assignment problem to find a globally optimal taxi-to-request assignment at each decision epoch. The authors compare the assignment-based strategy with two popular rule-based strategies. They evaluate dispatching strategies in detail in the city of Berlin and the neighboring region of Brandenburg using the microscopic large-scale MATSim simulator. The assignment-based strategy produced better results for both drivers (less idle driving) and passengers (less waiting). However, computing the assignments for thousands of taxis in a huge road network turned out to be computationally demanding. Certain adaptations pertaining to the cost matrix calculation were necessary to increase the computational efficiency and assure real-time responsiveness

A framework for agent based simulation of demand responsive transport systems

Demand responsive transport (DRT), such as shared mini busses, have become a viable form of public transport mainly in rural areas in recent years. In contrast to ordinary schedule-based services, DRT systems come in many different shapes and forms and are usually customised to the environment they operate in. E.g., they might be restricted to certain user groups or only operate in specific areas or with a specific fixed terminus. With advances in information and communications technology (ICT) and the possibility of driverless operations in the future, DRT systems may become an attractive additional mode also in urban and inter-urban transport. This brings the necessity to assess and evaluate DRT services and possible business models, with transport simulations being one possible way. This study introduces a framework for an extensible, open source shared minibus service simulation. Based on the agent based transport simulation MATSim and its existing DVRP extension, the extension provides DRT services as an additional mode to the synthetic population of a MATSim scenario. The module allows assigning vehicles to groups according to different dispatch algorithms shaped to the actual use case. In a first case study, a DRT system complements ordinary public transport and car infrastructure on the heavily used commuter relation between Braunschweig and Wolfsburg. During peak times, average travel times per traveler over all modes between the two cities can be reduced by 5 minutes using a fleet of 50 8-seat-vehicles. In a second case study, a DRT system is used to shuttle passengers in an area with non-optimal public transport access to the train station in Braunschweig. With given capacity constraints, the optimizer has to decide which customers to serve in order to achieve an on-time arrival for passenger

Using Multi-Agent Transport Simulations to Assess the Impact of EV Charging Infrastructure Deployment

Over the last two decades, electrification has gained importance as a means to decarbonise the transport sector. As the number of Electric Vehicles (EVs)increases, it is important to consider broader system aspects as well, especially when deciding the type, coverage, size and location of the charging infrastructure required. In this article, a Multi-Agent model depicting long distance transport in Sweden is proposed, allowing to simulate different scenarios and enabling a more detailed analysis of the interaction between these vehicles and the charging infrastructure

Analysis of Berlin's taxi services by exploring GPS traces

With current on-board GPS devices a lot of data is being collected while operating taxis. This paper focuses on analysing travel behaviour and vehicle supply of the Berlin taxi market using floating car data (FCD) for one week each in 2013 and 2014. The data suggests that there is generally a demand peak on workday mornings and a second peak over a longer time in the afternoon. On weekends, the demand peaks shift towards the night. On the supply side, drivers seem to adapt to the demand peaks very efficiently, with fewer taxis being available at times of low demand, such as during midday. A spatial analysis shows that most taxi trips take place either within the city centre or from/to Tegel Airport, the city's largest single origin and destination. Drivers spend a large amount of their work time on waiting for customers and the taxi rank at Tegel Airport is the most popular one