Veröffentlichungen
The content on this page was translated automatically.
| Lux, A.; Schneider, N.; Koch, J.; Sommer, C. | “The challenges of collecting data through real-world experiments in the context of a worldwide crisis,” in: Transportation Research Procedia, Volume 97, pp. 701–710, doi.org/10.1016/j.trpro.2026.04.208, 2026 |
| Harz, J.; Sommer, C. | “Surveying the travel behavior of city tourists—A concept for using a smartphone-based tracking app,” in: Transportation Research Procedia, Volume 97, pp. 220–230, doi.org/10.1016/j.trpro.2026.04.159, 2026 |
| Fouckhardt, L.; Sommer, C. | “The Methodology of a Quasi-Experimental, Mixed-Methods Study Using Different Survey Instruments,” in: Transportation Research Procedia, Volume 97, pp. 210–219, doi.org/10.1016/j.trpro.2026.04.158, 2026 |
| Henkel, F.; Briegel, R.; Fouckhardt, L.; Sommer, C. | “Tracking Application Versus Travel Diary: Analysis of the Method Effects,” in: Transportation Research Procedia, Volume 97, pp. 190–199, doi.org/10.1016/j.trpro.2026.04.156, 2026 |
| Koch, J.; Sommer, C. | “How gender-sensitive are our data collections? Emphasizing the need for a new way of thinking in transportation research,” in: Transportation Research Procedia, Volume 97, pp. 48–57, doi.org/10.1016/j.trpro.2026.04.142, 2026 |
| Fouckhardt, L.; Sommer, C.; Schneider, N. | “Modeling the infection risk in local public transport vehicles for aerosol-transmitted viruses,” in: Journal of Transport & Health, Volume 49, June 2026, doi.org/10.1016/j.jth.2026.102285, Elsevier, 2026 |
| Sommer, C.; Henkel, F.; Herget, M. | “The Distribution of External Costs of Transportation,” in: Schwedes, O.; Rammert, A.; Stark, K., Handbook of Transportation Policy, doi.org/10.1007/978-3-658-04777-1_55-1, Springer Verlag, Wiesbaden, 2026 |
| Kawgan-Kagan, I.; Koch, J.; Sommer, C. | “Data Gaps? Not Us! Typical Objections to a Lack of Data Equity in Transportation Planning and How We Can Respond,” in: doi.org/10.15495/EPub_UBT_00008872, 2026 |
| Schmidt, A.; Sommer, C.; Briegel, R.; Lambrecht, F. | “Quality-Based Evaluation of Traffic Signal Control for Public Transit,” in: Federal Highway and Transportation Agency, Reports of the Federal Highway and Transportation Agency, Transportation Engineering, Issue V 402, doi.org/10.60850/bericht-v402 (Traffic Engineering), Carl Ed. Schünemann KG, Bergisch Gladbach, 2025 |
| Henkel, F.; Sommer, C. | “Development and Application of a Method for the Quantification of Mobility Options,” in: Transportation Research Record: Journal of the Transportation Research Board; doi.org/10.1177/03611981251345765, 2025 |
| Koch, J.; Schneider, N.; Henninger, J.; Fouckhardt, L.; Sommer, C. | “Effects of Pandemic-Induced Staggered School Hours: The Case of the City of Herne,” in: Straßenverkehrstechnik, Vol. 69, No. 7, pp. 458–467, Kirschbaum Verlag GmbH, Bonn, 2025 |
| Barwisch, T.; Schneider, N.; Sommer, C.; Wolf, W. | “Between Time-Tested Practices, Current Requirements, and Future Trends—What Makes a Good Public Transit Plan?”, in: Straßenverkehrstechnik, Vol. 69, No. 6, pp. 387–391, Kirschbaum Verlag GmbH, Bonn, 2025 |
| Sommer, C.; Henkel, F.; Lanzendorf, M.; Rozynek, C.; Engbers, M.; Wilhelm, C.; Geschwinder, K.; Gapski, J.; Dietrich, A.-M.; Meier, N. | “Social2Mobility—Policy Brief: Social Participation and Mobility—Findings, Tools, and Recommendations for Integrated Transportation and Social Planning,” in: DOI:10.17170/kobra-2025032610996, 2025 |
| Benz, H.; Kepper, J.; Lometsch, M.; Sommer, C. | “The Legacy of Mobilfalt—Approaches for Further Developing Ridesharing Systems with a Mobility Guarantee,” in: DER NAHVERKEHR, Issue 05/2025, pp. 46–51, DVV Media Group GmbH, 2025 |
| Benz, H.; Kepper, J.; Lometsch, M.; Sommer, C. | “The Legacy of Mobilfalt—Project Goals and Design of the Innovative Transportation Service,” in: DER NAHVERKEHR, Issue 04/2025, pp. 38–44, DVV Media Group GmbH, 2025 |
| Henkel, F.; Fischer, A.; Sommer, C. | “Integrated Consideration of the Social and Ecological Dimensions of the Mobility Transition: Barriers to Using Sustainable Transport Systems by People at Risk of Poverty,” in: Journal of Urban Mobility, Volume 7, 100124, 2025, ISSN 2667-0917, Elsevier, 2025 |
| Harz, J.; Sommer, C. | “Modeling the mode of travel for city visitors,” in: Straßenverkehrstechnik, Vol. 69, No. 3, pp. 185–193, Kirschbaum Verlag GmbH, Bonn, 2025 |
| Koch, J.; Schneider, N.; Fouckhardt, L.; Sommer, C. | “How Can We Reduce the Risk of Infection in School Transportation During a Global Pandemic? Effects of Staggered School Hours,” in: ETC Conference Papers 2024, Online Conference Proceedings, Association for European Transport, 2025 |
| Sommer, C.; Schmidt, A.; Briegel, R. | “Methods for Evaluating Speed-Related Service Quality in Public Transit,” in: Straßenverkehrstechnik, Vol. 69, No. 1, pp. 31–37, Kirschbaum Verlag GmbH, Bonn, 2025 |
| Sacht, J.; Saake, S.; Sommer, C. | “True-Cost Pricing in Transportation—Concept and Exemplary Application of User-Pays Pricing in Private Transportation in Germany,” in: Straßenverkehrstechnik, Vol. 68, No. 12, pp. 980–985, Kirschbaum Verlag GmbH, Bonn, 2024 |
| Sommer, C.; Schneider, N.; Koch, J.; Fouckhardt, L.; Helfers, A.; Lux, A.; Volk, P.; Schlottbohm, B. | “Action Guide—Recommendations for Developing Pandemic-Resilient Public Transportation as Part of the EMILIA Research Project,” in: Department of Transportation Planning and Transportation Systems, University of Kassel, doi:10.17170/kobra-2024110611067, Kassel, 2024 |
| Sommer, C.; Milbradt, J.; Kahnt, S.; Otto-Zimmermann, K. | “Micro-mobility—Greater Sustainability Through Small Vehicles,” in: *https://doi.org/10.14512/9783987263385*, Oekom-Verlag, Munich, 2024 |
| Barwisch, T.; Schneider, N.; Sommer, C.; Wolf, W. | “Hesse: Updated Recommendations for the Revision of Local Public Transportation Plans,” in: DER NAHVERKEHR, Issue 04/2024, pp. 45–49, DVV Media Group GmbH, Hamburg, 2024 |
| Saake, S.; Budnitzki, A.; Sommer, C. | “Passenger Volume Forecasts in Public Transit: How Can the Quality of Forecast Results Be Evaluated?”, in: Straßenverkehrstechnik, Vol. 68, No. 8, pp. 615–622, Kirschbaum-Verlag, Bonn, 2024 |
| Sommer, C. | “Modal Split,” in: House of Logistics & Mobility GmbH (ed.), Glossary—Logistics and Mobility from A to Z, Frankfurt am Main, 2024 |
| Ebert, T.; Sommer, C.; Herget, M.; Briegel, R.; Milbradt, J. | “Deutschlandticket and Now? – An Immediate Public Transportation Program for More Passengers and Less CO2,” in: DER NAHVERKEHR, Issue 06/2024, pp. 06–10, DVV Media Group GmbH, Hamburg, 2024 |
| Fischer, A.; Rozynek, C.; Henkel, F.; Sommer, C. | “State of Research and Concepts on the Relationship Between Mobility and Social Exclusion,” in: Sommer, C.; Lanzendorf, M.; Engbers, M.; Wermuth, T. (eds.), Social Participation and Mobility. Fundamentals, Instruments, and Measures for Integrated Transportation and Social Planning, doi.org/10.1007/978-3-658-42536-4, Springer VS, 2024 |
| Henkel, F.; Fischer, A.; Sommer, C. | “Mobility Options, Mobility Behavior, and Mobility Barriers for Households with Children at Risk of Poverty,” in: Sommer, C.; Lanzendorf, M.; Engbers, M.; Wermuth, T. (eds.), Social Participation and Mobility. Fundamentals, Instruments, and Measures for Integrated Transportation and Social Planning, doi.org/10.1007/978-3-658-42536-4, Springer VS, 2024 |
| Henkel, F.; A.; Sommer, C. | “Development of an Index for Quantifying Mobility Options,” in: Sommer, C.; Lanzendorf, M.; Engbers, M.; Wermuth, T. (eds.), Social Participation and Mobility. Fundamentals, Tools, and Measures for Integrated Transportation and Social Planning, doi.org/10.1007/978-3-658-42536-4, Springer VS, 2024 |
| Fischer, A.; Henkel, F.; Sommer, C. | “Development and Exemplary Application of an Evaluation System Focusing on Social Impacts for Mobility-Related Measures,” in: Sommer, C.; Lanzendorf, M.; Engbers, M.; Wermuth, T. (eds.), Social Participation and Mobility. Fundamentals, Instruments, and Measures for Integrated Transportation and Social Planning, doi.org/10.1007/978-3-658-42536-4, Springer VS, 2024 |
| Sommer, C.; Lanzendorf, M.; Engbers, M.; Wermuth, T. (eds.) | “Social Participation and Mobility: Foundations, Instruments, and Measures for Integrated Transportation and Social Planning,” https://doi.org/10.1007/978-3-658-42536-4, Springer VS, 2024 |
| Harz, J.; Sommer, C. | “Modeling the Mode of Travel forCity Visitors,” in: Research Association for Road and Transportation Engineering, HEUREKA ’24, Conference Proceedings Online, FGSV 002/140, FGSV-Verlag, Cologne, 2024 |
| Henkel, F., Sommer, C. | “Methods for Quantifying Mobility Options,” in German Society for Road and Transportation Research, HEUREKA ’24, Online Conference Proceedings, FGSV 002/140, FGSV-Verlag, Cologne, 2024 |
| Koch, J.; Schneider, N.; Henninger, J.; Fouckhardt, L.; Sommer, C. | “Effects of Pandemic-Induced Staggered School Hours: The Case of the City of Herne,” in: Research Association for Road and Transportation Engineering, HEUREKA '24, Conference Proceedings Online, FGSV 002/140, FGSV-Verlag, Cologne, 2024 |
| Saake, S.; Budnitzki, A.; Sommer, C. | “Passenger Volume Forecasts in Public Transit: How Can the Quality of Forecast Results Be Evaluated?”, in: Research Association for Road and Transportation Engineering, HEUREKA '24, Online Conference Proceedings, FGSV 002/140, FGSV-Verlag, Cologne, 2024 |
| Fouckhardt, L.; Laufer, S.; Sauer, J.; Koch, J.; Schneider, N.; Sommer, C. | “Working Paper: Modeling the Infection Risk in Local Public Transport—Contact Number and Contact Time,” in: doi:10.17170/kobra-202401259432, 2024 |
| Leonhäuser, D.; Sommer, C. | “Estimation of Demand Effects of New Flexible Fare Products in Electronic Fare Management Systems for Public Transportation by Combining Survey and Passive Observation Data,” in: Transportation Research Procedia, Volume 76, 2024, Pages 208–221, Elsevier, 2024 |
| Helfers, A.; Schneider, N.; Koch, J.; Fouckhardt, L.; Sommer, C. | “Visualizing ventilation in the bus: Addressing risk perception among public transit passengers,” in: Transportation Research Part F: Psychology and Behavior, Volume 101, February 2024, pp. 236–249, Elsevier, 2024 |
| Kahnt, S. E.; Meenken, A.; Milbradt, J.; Müller-Görnert, M.; Sommer, C. | “Traffic and Space Shortages in Municipalities—Micro-Mobility as a Solution,” in: Donhauser, Ch.; Fuchs, T.; Saxinger, A., KommunalPraxis Special Edition, Issue 4/2023, December 2023, pp. 198–204, Wolters Kluwer Deutschland GmbH, Carl Link Kommunalverlag, Hürth, 2023 |
| Hasenbalg, C.; Rex, R.; Schween, S.; Schneider, N.; Helfers, A.; Sommer, C. | “Please Spread the Word! – A ‘Tell-a-Friend’ Campaign and Survey of Regular Customers in Frankfurt am Main During the Pandemic Fall of 2022,” in: Internationales Verkehrswesen, Issue 4/2023, pp. 56–60, Trialog Publishers Verlagsgesellschaft, Baiersbronn-Buhlbach, 2023 |
| Hasenbalg, C.; Rex, R.; Geiger, A.; Schneider, N.; Helfers, A.; Sommer, C. | “Why Do People Cancel Their Subscriptions?”, in: DER NAHVERKEHR, Issue 10/2023, pp. 40–44, DVV Media Group GmbH, Hamburg, 2023 |
| Sommer, C. | “Public Transit Services in Rural Areas,” in: Oswalt, P.; Rettich, St. (eds.), Series of the Department of Architecture, Urban Planning, and Landscape Architecture at the University of Kassel; “Centers 4.0—Spatial Policies and New Mobility in Rural Areas”; Vol. 8, jovis Verlag GmbH, ISBN 978-3-86859-622-9, Berlin, 2023 |
| Ebert, T.; Sommer, C.; Herget, M.; Briegel, R.; Milbradt, J. | “The Deutschlandticket—What’s Next?—An Immediate Public Transportation Program for More Passengers and Less CO2,” in: University of Kassel, Institute for Transportation, Local Transportation Days 2023. Transportation Transition and Public Transit: How Do We Get Everyone On Board Before the Train Leaves?, Transportation Series, Issue 36, Kassel University Press, ISBN 978-3-7376-1127-5, Kassel, 2023 |
| Sommer, C.; Kahnt, S. E.; Milbradt, J. | “Technical Standard for the Classification of Vehicles by Size (G-Classes),” Kassel, 2023 |
| Kahnt, S. E.; Milbradt, J.; Sommer, C. | “‘G’ Classes for Vehicle Classification According to Size and the Justification of ‘Fine Mobility’,” in: HCI in Mobility, Transport, and Automotive Systems; 5th International Conference, MobiTAS 2023, Held as Part of the 25th HCI International Conference, HCII 2023, Copenhagen, Denmark, July 23–28, 2023, Proceedings, Part I, pp. 282–295, Springer Verlag, 2023 |
| Sommer, C. | “Commentary on the Article: From the 9-Euro Ticket to the Deutschlandticket: Are Discounted Flat-Rate Tickets a Game-Changer for the Transportation Transition? (by Oliver Mietzsch),” in: Journal of Transportation Science, Vol. 93, No. 1, p. 14, Verkehrs-Verlag J. Fischer, Düsseldorf, 2023 |
| Sommer, C.; Ebert, T.; Herget, M.; Briegel, R.; Milbradt, J. | “Public Transit Emergency Program—The Package of Measures for the Transportation Transition by 2025,” in: Study by MultiMOBIL GmbH commissioned by Greenpeace, Kassel, 2023 |
| Sommer, C.; Briegel, R.; Harz, J.; Reiserer, M. | “Action Guide to Climate Neutrality in Mobility for the City of Kassel,” in: doi:10.17170/kobra-202302017438, Kassel, 2023 |
| Saake, S.; Sommer, C. | “Design of a Forecasting Method for Occupancy Rates in Local Public Transport Based on Data from Automatic Passenger Counting Systems,” in: Advances in Resilient and Sustainable Transport - Proceedings of the 6th Interdisciplinary Conference on Production, Logistics and Traffic 2023, pp. 13–28, Springer Verlag, 2023 |
| Sommer, C.; Henkel, F.; Fischer, A.; Lanzendorf, M.; Rozynek, C.; Engbers, M.; Geschwinder, K.; Gapski, J.; Dietrich, A.-M.; Meier, N. | “Social2Mobility Policy Brief. Preventing Mobility Poverty. How Can Social Participation Through Mobility Be Enabled Within the Framework of Integrated Transportation, Land-Use, and Social Planning?”, in: Working Papers on Mobility Research No. 34, DOI: https://doi.org/10.21248/gups.58871, Mobility Research Working Group, Institute for Human Geography, Goethe University Frankfurt am Main, Frankfurt am Main, 2023 |
| Harz, J.; Sommer, C. | “Collection of Revealed Preference Mobility Data of City Tourists—a Two-part Survey Design,” in: Proceedings of the 27th International Conference on Urban Development, Regional Planning, and Information Society, REAL CORP 2022, Vienna, 2022 |
| Otto-Zimmermann, K.; Kahnt, S. E.; Milbradt, J.; Sommer, C. | “GGG Classes for Vehicles—Classification by Size, Weight, and Speed and the Rationale for Micro-Mobility,” in: Internationales Verkehrswesen, Issue 4/2022, pp. 57–59, Trialog Publishers Verlagsgesellschaft, Baiersbronn-Buhlbach, 2022 |
| Schneider, N.; Helfers, A.; Reiserer, M.; Sommer, C. | “Subjective Perception of Risk in Public Transit During the Pandemic—Safety from the Passenger’s Perspective,” in: DER NAHVERKEHR, Issue 11/2022, pp. 18–22, DVV Media Group GmbH, Hamburg, 2022 |
| Harz, J.; Sommer, C. | “Mode Choice of City Tourists: Discrete Choice Modeling Based on Survey Data from a Major German City,” in: Transportation Research Interdisciplinary Perspectives 16, December 2022, Article 100704, Elsevier, 2022 |
| Herget, M.; Gies, J.; Sommer, C. | “Transforming Mobility in Rural Areas—Initial Findings from the ‘LandMobil—On the Move in Rural Areas’ Funding Initiative,” in: DER NAHVERKEHR, Issue 09/2022, pp. 78–81, DVV Media Group GmbH, Hamburg, 2022 |
| Fischer, A.; Sommer, C. | “Development of a GIS-Based Method for Analyzing Mobility Equity—Using the Example of Bicycle Traffic in the Municipality of Langenhagen in the Hanover Region,” in: Journal for Mobility and Transportation, Issue 14, German Society for Transportation Science e. V., Berlin, 2022 |
| Brandstäter, S.; Sommer, C. | “Potential Applications of Public Transit-Based Transport Systems with a Focus on Pharmacy Deliveries in Kassel,” in: Road Traffic Engineering, Vol. 66, No. 7, pp. 501–507, Kirschbaum-Verlag, Bonn, 2022 |
| Lambrecht, F.; Sommer, C. | “SafeBike—a road safety program for young adolescent cyclists,” in: Plant, K. and Praetorius, G. (eds.), Human Factors in Transportation, AHFE (2022) International Conference, AHFE Open Access, vol. 60, AHFE International, USA, 2022 |
| Helfers, A.; Reiserer, M.; Schneider, N.; Ebersbach, M.; Sommer, C. | “Should I Stay or Should I Go? Risk Perception and Use of Local Public Transportation During the COVID-19 Pandemic,” in: Frontiers in Psychology, 2022 |
| Harz, J.; Sommer, C. | “Success Factors and Barriers to Integrated Ridesharing in Rural Areas,” in: Straßenverkehrstechnik, Vol. 66, No. 6, pp. 417–424, Kirschbaum-Verlag, Bonn, 2022 |
| Sommer, C.; Briegel, R.; Harz, J.; Reiserer, M. | “Strategies for Meeting Climate Protection Goals in Transportation—An Integrated Push-and-Pull Strategy Is Required at All Planning Levels,” in: DER NAHVERKEHR, Issue 05/2022, pp. 06–11, DVV Media Group GmbH, Hamburg, 2022 |
| Faulhaber, A. K.; Hegenberg, J.; Kahnt, S. E.; Lambrecht, F.; Leonhäuser, D.; Saake, St.; Wehr, F.; Schmidt, L.; Sommer, C. | “Development of a Passenger Assistance System to Increase the Attractiveness of Local Public Transport,” in: Sustainability 2022, 14, 4151, MDPI, Switzerland, Basel, 2022 |
| König, I.; Bachmann, M.; Bieshaar, M.; Schindler, St.; Lambrecht, F.; David, K.; Sick, B.; Hornung, G.; Sommer, C.; Francke, A. | “Traffic Safety in Future Cities Using a Safety Approach Based on AI and Wireless Communications,” in: Mobile Communication - Technologies and Applications; 25th ITG Symposium, pp. 1–6, 2021 |
| Harz, J.; Sommer, C. | “Determinants of Success and Constraints of Integrated Ridesharing in Rural Areas,” in: Transportation Research Interdisciplinary Perspectives 11, September 2021, Article 100459, Elsevier, 2021 |
| Briegel, R.; Sommer, C. | “Multi-Agent Systems for Modeling Mode Choice,” in: Research Association for Road and Transportation Engineering, HEUREKA ’21, Conference Proceedings Online, FGSV 002/127, FGSV-Verlag, Cologne, 2021 |
| Leonhäuser, D.; Sommer, C. | “Flexible Fares for Public Transit,” in: German Society for Road and Transportation Research, HEUREKA '21, Conference Proceedings Online, FGSV 002/127, FGSV-Verlag, Cologne, 2021 |
| Harz, J.; Sommer, C. | “Success Factors and Barriers to Integrated Ridesharing in Rural Areas,” in: Research Association for Roads and Transportation, HEUREKA '21, Online Conference Proceedings, FGSV 002/127, FGSV-Verlag, Cologne, 2021 |
| Bieland, D.; Sommer, C. | “Impact Assessment of Alternative Financing Instruments in Public Transit: The Case of the Rhine-Main Transport Association,” in: Research Association for Road and Transportation Engineering, HEUREKA '21, Online Conference Proceedings, FGSV 002/127, FGSV-Verlag, Cologne, 2021 |
| Lambrecht, F.; Sommer, C. | “Critical Behavior of Young Adolescent Cyclists in Germany,” in: Ahram, T. Z.; Karwowski, W.; Kalra, J. (eds.), Advances in Artificial Intelligence, Software and Systems Engineering —Proceedings of the AHFE 2021 Virtual Conferences on Human Factors in Software and Systems Engineering, Artificial Intelligence and Social Computing, and Energy, July 25–29, 2021, USA, Springer Verlag, 2021 |
| Sommer, C.; Deutsch, V. | “Fundamentals and Forms of Public Transit,” in: Vallée, D.; Engel, B.; Vogt, W. (eds.), Urban Transportation Planning, Vol. 3: Design, Sizing, and Operation, 3rd ed., Springer Viewig, Berlin, Heidelberg, 2021 |
| Sommer, C.; Deutsch, V. | "Local Transit Planning and Public Transit Network Design," in: Vallée, D.; Engel, B.; Vogt, W. (eds.), Urban Transportation Planning, Vol. 3: Design, Capacity Analysis, and Operations, 3rd ed., Springer Viewig, Berlin, Heidelberg, 2021 |
| Sommer, C.; Deutsch, V. | “Planning and Design of Public Transit Facilities,” in: Vallée, D.; Engel, B.; Vogt, W. (eds.), Urban Transportation Planning, Vol. 3: Design, Sizing, and Operation, 3rd ed., Springer Vieweg, Berlin, Heidelberg, 2021 |
| Sommer, C.; Saighani, A.; Leonhäuser, D. | “Economic Evaluation of Urban Transportation Systems: Costs of Urban Transportation—What Are the True Costs of Different Modes of Transportation?”, Springer Vieweg, Berlin, Heidelberg, 2021 |
| Sommer, C.; Bieland, D. | “Estimating the Impact on Demand of Introducing an Affordable Annual Pass,” in: Journal of Transportation Science, Vol. 91, No. 2, pp. 88–113, Verkehrs-Verlag J. Fischer, Düsseldorf, 2021 |
| Sommer, C.; Reiserer, M.; Wollnitza, P. | “Risk of Infection When Using Local Public Transit: The Case of SARS-CoV-2,” in: Road Traffic Engineering, Vol. 4/2021, pp. 251–257, Kirschbaum Verlag, Bonn, 2021 |
| Sommer, C. | "Future Financing of Local Public Transit," in: V+T Verkehr und Technik, Issue 3/2021, pp. 75–78, Erich Schmidt Verlag, Berlin, 2021 |
| Sommer, C. | Statement on the topic “Future Models for the Financing and Organization of Local Public Transit,” Committee on Transport and Digital Infrastructure of the German Bundestag, Public Hearing on January 13, 2021, in Berlin |
| Herget, M.; Sommer, C.; Gies, J. | “Sustainable Public Transportation in Rural Areas: Challenges and Key Decisions,” in: Internationales Verkehrswesen, Issue 2/2021, pp. 12–15, Trialog Publishers Verlagsgesellschaft, Baiersbronn-Buhlbach, 2021 |
| Oswald, T.; Sommer, C. | “Free Public Transit?: Research Study Examines the Effects of Free Public Transit on Mobility Behavior,” in: DER NAHVERKEHR, Issue 12/2020, pp. 40–44, DVV Media Group, Hamburg, 2020 |
| Bieland, D.; Sommer, C. | “New Modes of Financing Public Transport in Germany—Estimating the Impacts of Three Tariff and Financing Instruments on Demand and Revenue,” in: Finnish Transport and Communications Agency, TRA 2020—Rethinking Transport (Conference canceled) (accepted for publication), Finnish Transport and Communications Agency, Helsinki, 2020 |
| Leonhäuser, D.; Sommer, C. | “New Tariffs for Electronic Fare Management Systems in Public Transport,” in: Finnish Transport and Communications Agency, TRA 2020 – Rethinking Transport (Conference Canceled) (accepted for publication), Finnish Transport and Communications Agency, Helsinki, 2020 |
| Briegel, R.; Daskalakis, M.; Sommer, C. | “Simulation of effects of ride sharing interconnected with public transport in rural areas,” in: Finnish Transport and Communications Agency, TRA 2020 - Rethinking transport (Conference canceled) (accepted for publication), Finnish Transport and Communications Agency, Helsinki, 2020 |
| Harz, J.; Sommer, C. | “Determinants of success and constraints of integrated ridesharing in rural areas,” in: Finnish Transport and Communications Agency, TRA 2020 - Rethinking transport (Conference canceled) (accepted for publication), Finnish Transport and Communications Agency, Helsinki, 2020 |
| Sommer, C.; Harz, J. | “How Can Ridesharing Become an Important Part of a Sustainable Public Transportation System in Rural Areas?”, in: GetMobil - Policy Brief 2, Kassel, 2019 |
| Sommer, C.; Harz, J. | “Integrated Ridesharing in Rural Areas,” in: Nahverkehrs-praxis, Issue 11/12-2019, pp. 16–18, Fachverlag Dr. H. Arnold GmbH, Dortmund, 2019 |
| Daskalakis, M.; Sommer, C.; Roßnagel, A.; Kepper, J. | Daskalakis, M.; Sommer, C.; Roßnagel, A.; Kepper, J. (Eds.),** Connecting Rural Mobility—Ridesharing in Rural Areas and Its Integration into Public Transit, oekom Verlag, ISBN 978-3-96238-161-5, Munich, 2019 |
| Harz, J.; Sommer, C. | “Evaluation of the Measures Implemented in the Real-World Experiment,” in: Daskalakis, M.; Sommer, C.; Roßnagel, A.; Kepper, J. (eds.), Connecting Rural Mobility—Ridesharing in Rural Areas and Its Integration into Public Transit, oekom Verlag, Munich, 2019 |
| Harz, J.; Sommer, C. | “Flinc System Analysis,” in: Daskalakis, M.; Sommer, C.; Roßnagel, A.; Kepper, J. (eds.), Connecting Rural Mobility—Ridesharing in Rural Areas and Its Integration into Public Transit, oekom Verlag, Munich, 2019 |
| Harz, J.; Sommer, C. | “Potential and Barriers to Ridesharing from a Transportation Science Perspective,” in: Daskalakis, M.; Sommer, C.; Roßnagel, A.; Kepper, J. (eds.), Connecting Rural Mobility—Ridesharing in Rural Areas and Its Integration into Public Transit, oekom Verlag, Munich, 2019 |
| Harz, J.; Benz, H.; Sommer, C. | “Integrating Ridesharing into Public Transit,” in: Daskalakis, M.; Sommer, C.; Roßnagel, A.; Kepper, J. (eds.), Connecting Rural Mobility—Ridesharing in Rural Areas and Its Integration into Public Transit, oekom Verlag, Munich, 2019 |
| Leonhäuser, D.; Dietrich, A.-M.; Sommer, C.; Sauer, J. | “Flexible Fares Put to the Test,” in: DER NAHVERKEHR, Issue 10/2019, pp. 66–70, DVV Media Group GmbH, Hamburg, 2019 |
| Leonhäuser, D.; Sommer, C. | “Development and Impact Assessment of Flexible Fares in EFM Systems,” in: Nahverkehrs-Tage 2019. Financing Public Transportation: Between Performance-Based E-Fares, Affordable Flat Rates, and Third-Party User Financing, Transportation Series, Issue 30, Kassel University Press, ISBN 978-3-7376-0752-0 (print), 978-3-7376-0753-7 (e-book), Kassel, 2019 |
| Sommer, C.; Saighani, A. | “Public Transit Service Models in Rural Areas,” in: Handbook of Municipal Transportation Planning, VDE Verlag, Berlin, 2019 |
| Sommer, C.; Bieland, D. | “Automatic Collection of Passenger Demand,” in: Nahverkehrs-praxis, Issue 6-2019, pp. 36–38, Fachverlag Dr. H. Arnold GmbH, Dortmund, 2019 |
| Klingauf, A.; Hegenberg, J.; Lambrecht, F.; Bieland, D.; Schmidt, L.; Sommer, C. | “User Requirements for a Public Transportation Assistance System: Interdisciplinary Analysis, Evaluation, and Design,” in: 65th Congress of the Society for Ergonomics, February 27–March 1, 2019, Society for Ergonomics e. V., B.2.6., GfA-Press: Dortmund, Dresden, 2019 |
| Saighani, A.; Sommer, C. | “Method for an Economic Assessment of Urban Transport Systems,” in: Elsevier 2019, *Transportation Research Procedia*, Volume 37; pp. 282–289. DOI: 10.1016/j.trpro.2018.12.194, 2019 |
| Sommer, C.; Dahlmann-Resing, T.; Deutsch, V.; Schmidt, A. | “Reliable Public Transportation,” in: German Road and Transportation Congress 2018, Conference Proceedings Erfurt, pp. 1–9, FGSV-Verlag, Erfurt, 2018 |
| Sommer, C.; Bieland, D. | “The ‘Vienna Model’—A Model for German Cities?”, in: DER NAHVERKEHR, Issue 09/2018, pp. 53–61, Alba Fachverlag, Düsseldorf, 2018 |
| Kagerbauer, M.; Nobis, C.; Sommer, C.; Gertz, C.; Ackermann, T.; Loose, W. | “Definitions of ‘Multi- and Intermodality’,” in: Straßenverkehrstechnik, Vol. 62, No. 5, pp. 366–372, Kirschbaum-Verlag, Bonn, 2018 |
| Sommer, C.; Bieland, D. | “Analysis of the Effects of Introducing Affordable Annual Tickets in Vienna,” in: Proceedings of the 7th Transport Research Arena (TRA) 2018, April 16–19, 2018, Vienna, Austria, 2018 |
| Sommer, C.; Harz, J. | “Determination of Potentials for Drivers and Passengers of Integrated Ridesharing Services in Rural Areas,” in: Proceedings of the 7th Transport Research Arena (TRA) 2018, April 16–19, 2018, Vienna, Austria, 2018 |
| Witte, C.; Sommer, C. | “Customers’ Demands for Multimodal Fares,” in: Proceedings of the 7th Transport Research Arena (TRA) 2018, April 16–19, 2018, Vienna, Austria, 2018 |
| Lambrecht, F.; Sommer, C. | “Ticket sharing—a model for a sharing fare in public transit,” in: Proceedings of the 7th Transport Research Arena TRA 2018, April 16–19, 2018, Vienna, Austria, 2018 |
| Sommer, C. | “Commentary on the article: Mobility in Rural Areas: An Investigation of the Motivation for Volunteer Work in Community Bus Associations (by Thomas Pitz, Jörn Sickmann, Wolf Gardian, Hasan Alkas, and Irmgard Buder),” in: Journal of Transportation Science, Vol. 88, No. 3, pp. 263–268, Verkehrs-Verlag J. Fischer, Düsseldorf, 2017 |
| Saighani, A.; Leonhäuser, D.; Sommer, C. | “Methods for the Economic Evaluation of Urban Transportation Systems,” in: Road Transportation Technology, Vol. 61, No. 10, pp. 695–704, Kirschbaum-Verlag, Bonn, 2017 |
| Leonhäuser, D.; Sommer, C. | “Analysis of Usage Data from E-Ticketing Systems,” in: University of Kassel, Institute of Transportation, Local Public Transportation Days 2017. Digital and Disruptive—New Data and Methods for Customer-Oriented Public Transportation, Transportation Series, Issue 28, Kassel University Press, ISBN 978-3-7376-0370-6 (print), 978-3-7376-0371-3 (e-book), Kassel, 2017 |
| Witte, C.; Sommer, C. | “Potential Demand for Multimodal Fares Taking into Account the Preferences of Public Transit Customers,” in: Research Association for Road and Transportation Engineering; Association of German Transportation Companies, HEUREKA ’17 Optimization in Traffic and Transportation, FGSV-Verlag, Cologne, 2017 |
| Schmitt, V.; Sommer, C. | “Impact Analysis and Evaluation of Passenger-Carrying Systems Integrated into Public Transit,” in: Research Association for Road and Transportation; Association of German Transportation Companies, HEUREKA ’17 Optimization in Traffic and Transportation, FGSV-Verlag, Cologne, 2017 |
| Sommer, C.; Leonhäuser, D.; Mucha, E. | “Effects of Environmentally Oriented Transportation Concepts on the Municipal Budget,” Final Report—Full Version, Federal Environment Agency, Dessau-Roßlau, 2016 |
| Sommer, C.; Mucha, E.; Roßnagel, A.; Anschütz, M.; Hentschel, A.; Loose, W. | “Environmental and Cost Benefits of Selected Innovative Mobility and Transportation Concepts in Urban Passenger Transport,” Final Report—Full Version, Federal Environment Agency, Dessau-Roßlau, 2016 |
| Sommer, C.; Lambrecht, F. | “Concepts for Tenant Tickets to Connect Housing and Transportation,” in: Elsevier 2016, *Transportation Research Procedia—Transforming Urban Mobility. mobil.TUM 2016*, Volume 19, pp. 40–48, Munich, 2016 |
| Lambrecht, F., Sommer, C. | “Concepts for tenant tickets to link housing and transportation,” in: Mayr H. C., Pinzger M. (eds.), INFORMATIK 2016. Lecture Notes in Informatics (LNI), Volume P‑259, 1349‑1362, GI Bonn. ISBN 978‑3‑88579‑653‑4, ISSN 1617‑5468, Klagenfurt, 2016 |
| Sommer, C. | “Mobility Behavior,” in: Ostermann, N.; Rollinger, W. (eds.), “Handbook of Public Transportation—Focus on Austria,” DVV Media Group, Hamburg, 2016 |
| Macoun, T.; Schopf, M.; Sommer, C. | “The Impact of Spatial Planning on Transportation,” in: Ostermann, N.; Rollinger, W. (eds.), “Handbook of Public Transportation—Focus on Austria,” DVV Media Group, Hamburg, 2016 |
| Sommer, C.; Sauer, J. | “Fare Structuring and Revenue Sharing,” in: Ostermann, N.; Rollinger, W. (eds.), “Handbook of Public Transportation—Focus on Austria,” DVV Media Group, Hamburg, 2016 |
| Sommer, C.; Schäfer, F.; Löcker, G. | “Structured Planning for Public Transit—A Guide to Public Transit Planning in Rural Areas Is Now Available,” in: DER NAHVERKEHR, Vol. 10/2016, Alba Fachverlag, Düsseldorf, 2016 |
| Saighani, A.; Sommer, C. | “Potentials for Reducing Carbon Dioxide Emissions and the Use of Renewable Energy in the Regional Transportation Market,” in: Elsevier 2017, Transportation Research Procedia – World Conference on Transport Research – WCTR 2016, Volume 25, Pages 3483–3498, Shanghai, 2016 |
| Bieland, D.; Sommer, C.; Witte, C. | “Uncommon leisure traffic—Analyses of travel behavior of visitors,” in: Elsevier 2017, Transportation Research Procedia – World Conference on Transport Research – WCTR 2016, Volume 25, Pages 3975–3988, Shanghai, 2016 |
| Bieland, D.; Sommer, C.; Witte, C. | “A survey-based analysis of traffic behavior of short-stay vacationers and same-day visitors,” in: Elsevier 2016, Transportation Research Procedia – Transport Research Arena TRA 2016, Volume 14, pp. 3228–3237, Warsaw, 2016 |
| Sommer, C.; Leonhäuser, D. | “Method for Allocating Municipal Transportation-Related Expenditures and Revenues by Transportation System,” in: Handbook of Municipal Transportation Planning, VDE-Verlag, Berlin, 2016 |
| Sommer, C.; Sauer, J. | “Flexible Fares,” in: Nahverkehrs-praxis, Issue 1/2-2016, Fachverlag Dr. H. Arnold GmbH, Dortmund, 2016 |
| Sommer, C.; Schäfer, F.; Löcker, G.; Hattop, T.; Saighani, A. | “Mobility and Service Strategies in Rural Areas—Planning Guide for Action Options for Public Transit Authorities and Transit Companies, with Special Consideration of the Economic Aspects of Flexible Service Models,” in: Federal Ministry of Transport and Digital Infrastructure (BMVI), Berlin, 2016 |
| Bieland, D.; Sommer, C.; Witte, C. | “Mobility Behavior in Non-Routine Leisure Travel,” in: Proff, Heike, Fojcik, Thomas Martin (eds.), “National and International Trends in Mobility—Technical and Business Aspects, ” Proceedings of the 7th Science Forum on Mobility held in June 2015 at the University of Duisburg-Essen, Gabler Verlag, ISBN 978-3-658-14562-0 (paperback), ISBN 978-3-658-14563-7 (e-book), Wiesbaden, 2016 |
| Sommer, C.; Bieland, D.; Witte, C. | “Traffic Behavior in Non-Routine Leisure Travel,” in: ZfAW—Journal for the Entire Automotive Industry Value Chain, Vol. 18, No. 3/2015, FAW-Verlag, Bamberg, 2015 |
| Sommer, C.; Bieland, D.; Schmidt, L.; Kniewel, R.; Braun-Lüdicke, E. | “Concepts for Environmentally Friendly Tourism in Northern Hesse,” in: DER NAHVERKEHR, Vol. 7–8/2015, Alba Fachverlag, Düsseldorf, 2015 |
| Sommer, C. | “Public Transit Needs Generalists—Part-Time Master’s Program in Public Transit + Mobility for Executives at the University of Kassel,” in: Internationales Verkehrswesen, Issue 2/2015, DVV Media Group GmbH, Hamburg, 2015 |
| Sommer, C.; Ebert, T.; Habbishaw, K.; Saighani, A.; Rühl, M.; Jungermann, M. | “Energy Transition in Northern Hesse: Potential for Reducing CO2 Emissions and the Transition to Renewable Energy in the Regional Transportation Market,” in: Fraunhofer IWES, Stadtwerke Union Nordhessen, GRIN Verlag, ISBN 978-3-656-93205-5, ISBN 978-3-656-93204-8 (e-book), Munich, 2015 |
| Sommer, C.; Leonhäuser, D. | “Cost Comparison for Municipal Transportation Systems—Development and Application of a Method for Allocating Municipal Subsidies by Transportation System,” in: Straße und Autobahn, Vol. 66, No. 3, Kirschbaum-Verlag, Bonn, 2015 |
| Sommer, C.; Schmitt, V. | “'Mobilfalt'—A Ride-Sharing System to Complement Public Transit,” in: Deutscher Landkreistag e.V., Der Landkreis, 03/2015, Verlag W. Kohlhammer GmbH, Stuttgart, 2015 |
| Mucha, E.; Sommer, C. | “Integration of New Services into Traditional Public Transit,” in: University of Kassel, Institute for Transportation (ed.): Local Transit Days 2013. New Concepts for Urban and Rural Areas. Transportation Series, Issue 24, ISBN 978-3-86219-786-6 (print), ISBN 978-3-86219-787-3 (e-book), Kassel University Press, Kassel 2014 |
| Sommer, C.; Mucha, E. | “Innovative Urban Mobility Concepts,” in: “TRA (Transport Research Arena) 2014, 5th Conference ‘Transport Solutions: from Research to Deployment, Innovate Mobility, Mobilize Innovation!’, Paris, 2014 |
| Sommer, C.; Mucha, E. | “Integrated Multimodal Mobility Services,” in: Proff, Heike (ed.), “Radical Innovations in Mobility—Technical and Business Aspects, ” conference proceedings of the 5th Science Forum on Mobility held in June 2013 at the University of Duisburg-Essen, Gabler Verlag, ISBN 978-3-658-03101-5 (paperback), ISBN 978-3-658-03102-2 (e-book), Wiesbaden, 2014 |
| Sommer, C.; Witte, C. | “Urban Freight Transport,” in: Roßnagel, Alexander (ed.): “Regional Climate Adaptation: Challenges—Solutions—Obstacles—Implementation Using Northern Hesse as an Example,” Kassel University Press, ISBN 978-3-86219-660-9, 2013, 794 pages, (Interdisciplinary Research on Climate Change Mitigation and Adaptation 5), Kassel, 2013 |
| Sommer, C. | “New Master’s Program at the University of Kassel,” in: Nahverkehrs-praxis, Issue 9-2013, Fachverlag Dr. H. Arnold GmbH, Dortmund, 2013 |
| Sommer, C.; Schmitt, V. | “Mobilfalt – Integration of Ride-Sharing into Public Transport as a New Approach for Rural Areas,” in: Proceedings of the 13th WCTR, Rio de Janeiro, 2013 |
| Schmitt, V.; Bauer, B.; Sommer, C. | “What Do Bicycle Traffic, Pedestrian Traffic, Local Public Transit, and Motor Vehicle Traffic Cost a Municipality?—Development and Application of a Method for Comparing Different Modes of Transportation Based on Municipal Budgets,” in: Schrenk, M; Popovich, V.; Zeile, P., REAL CORP 2012, Proceedings, ISBN 978-3-9503110-5-1, Schwechat, 2013 |
| Sommer, C.; Mucha, E. | “Multimodal Services to Complement Traditional Public Transit,” in: DER NAHVERKEHR, Vol. 06/2013, Alba Fachverlag, Düsseldorf, 2013 |
| Sommer, C. | “Continuing Education in Public Transit and Mobility,” in: DER NAHVERKEHR, Vol. 05/2013, p. 39ff, Alba Fachverlag, Düsseldorf, 2013 |
| Schmitt, V.; Sommer, C. | “Mobilfalt”—A Ride-Sharing System to Complement Public Transit in Rural Areas,” in: Proff, H., Pascha, W., Schönharting, J., Schramm, D. (eds.), “Steps Toward Future Mobility—Technical and Business Aspects, ” Proceedings of the 4th Mobility Science Forum held in June 2012 at the University of Duisburg-Essen, Gabler Verlag, ISBN 978-3-8349-4307-1 (paperback), ISBN 978-3-8349-4308-8 (e-book), Wiesbaden, 2013 |
| Sommer, C. | “Development of Individual Travel Behavior Against the Background of Changing Framework Conditions,” in: German Society for Transportation Science (DVWG) Annual Volume 2011/2012 “Perspectives on Mobility—Challenges in a Changing Society,” Berlin, 2013 |
| Sommer, C.; Eikenberg, O. | “Bus Lanes,” in: Handbook of Municipal Transportation Planning, Volume 4, Chapter 5: Design of Individual Transportation System Facilities, VDE-Verlag, Berlin, 2012 |
| Hunsicker, F.; Sommer, C. | “Mobility Costs 2030: Price Increases Will Continue in the Long Term,” in: International Transportation, Issue 4/2012, DVV Media Group, Hamburg, 2012 |
| Schmitt, V.; Sommer, C. | “Ride-Sharing Systems as a Complement to Local Public Transit in Rural Areas—The Example of Mobilfalt,” in: Schrenk, M.; Popovich, V.; Zeile, P. (eds.): REAL CORP 2012, Proceedings, Schwechat, 2012 |
| Sommer, C.; Krichel, P. | “Who Uses Which Modes of Transportation,” in: Der Nahverkehr, Vol. 03/2012, pp. 15–21, Alba Fachverlag, Düsseldorf, 2012 |
| Krichel, P.; Eikenberg, O.; Sommer, C. | “City Logistics as a Tool for Climate Protection and Climate Adaptation? – Methodology and Results of a Potential Study,” in: RWTH Aachen, Institute for Urban Planning and Urban Transportation, AMUS 2011, Climate Change: Proportionality and Scope—Implications for Urban, Regional, and Transportation Planning, E-Paper E2 City Region Country (1/2011), Aachen, 2011 |
| Sommer, C.; Bartels, S.; Sauer, J.; Spichal, M. | “Accurately Measuring Travel Demand—Quality Standards and Management in Passenger Surveys,” in: Der Nahverkehr, Vol. 5/2011, pp. 30–36, Transportation Planning, Alba Fachverlag, Düsseldorf, 2011 |
| Witte, C.; Krichel, P.; Sommer, C. | “Shifting Delivery Traffic to Bicycle Couriers—Methodology and Results of a Feasibility Study,” in: Prof. Dr.-Ing. U. Clausen, Fraunhofer IML, Dortmund, “Logistics, Transportation, and Environment” series, Commercial Transportation 2011: Models—Strategies—Sustainability, Praxiswissen Publishing, Dortmund, 2011 |
| Bäumer, M.; Hautzinger, H.; Kathmann, T.; Schmitz, S.; Sommer, C.; Wermuth, M. | “Determination of Standards for Requirements-Based Data Quality in Traffic Surveys,” in: Straßenverkehrstechnik, Vol. 54, No. 10, pp. 660–663, and Vol. 55, No. 1, pp. 40–43, Kirschbaum-Verlag, Bonn, 2010 and 2011 |
| Bäumer, M.; Hautzinger, H.; Kathmann, T.; Schmitz, S.; Sommer, C.; Wermuth, M. | “Determination of Standards for Requirements-Based Data Quality in Traffic Surveys,” in: Federal Highway Research Institute, Traffic Engineering Series, Issue V 200, NW-Verlag, Bremerhaven, 2010 |
| Hunsicker, F.; Sommer, C. | “Mobility Costs in 2030: Driving and Public Transit Use Will Become More Expensive,” in: Internationales Verkehrswesen, Vol. 61, No. 10, pp. 367–376, Deutscher Verkehrs-Verlag, Hamburg, 2009 |
| Bley, O.; Sommer, C.; Lüke, K.-H.; Schlüter, W.; Telschow, A.; Wermuth, M. | “Location-based mobile ticketing with electronic fare management,” in: IPTS Conference, Conference Proceedings, Amsterdam, 2008 |
| Böhm, A.; Murtz, B.; Sommer, C.; Wermuth, M. | “Location-based ticketing in public transport,” in: Welfens, P.J.J.; Walther-Klaus, E., *Digital Excellence*, Springer-Verlag, Berlin, 2008 |
| Hunsicker, F.; Sommer, C. | “What Kind of Future Would You Like?”, in: Internationales Verkehrswesen, Issue 9, Deutscher Verkehrs-Verlag, Hamburg, 2008 |
| Sommer, C.; Böhm, A.; Murtz, B.; Wermuth, M. | “Use of Modern Location Technologies for Mobile Phone Ticketing Systems,” in: Federal Ministry of Economics and Technology, Traffic Management and Transportation Technologies—A Mobile Future with Intelligent Transportation Systems, Berlin, 2008 |
| Sommer, C.; Bartels, S.; Beblik, A. | “PDA or Questionnaire?—Tools for Passenger Surveys,” in: DER NAHVERKEHR, Issue 7–8, Alba Fachverlag, Düsseldorf, 2008 |
| Sommer, C. | “Ring & Ride—Multifunctional, Mobile-Based Cell Phone Ticketing,” in: Final Report on the WVI GmbH Subproject, WVI GmbH, Braunschweig, 2008 |
| Sommer, C.; Wermuth, M. | “Recent Developments in Mobile Ticketing,” in: DER NAHVERKEHR, Issue 7–8, Alba Fachverlag, Düsseldorf, 2007 |
| Chlond, B.; Sommer, C.; Beckmann, K.-J.; Huber, F. | “Transportation Consequences of Demographic Change,” in: Straßenverkehrstechnik, Issue 10, Kirschbaum-Verlag, Bonn, 2006 |
| Hegner, S.; Sommer, C. | “Youth Participation in Planning—Future Workshop in Lingen (Ems),” in: SRL—Association for Urban, Regional, and State Planning e.V., PLANERIN 4, pp. 43–44, Berlin, 2006 |
| Wermuth, M.; Sommer, C.; Wulff, S. | “Survey of Individual Route Choice for the Further Development of Traffic Redistribution Models,” in: Federal Highway Research Institute, Transportation Engineering Series, Issue V 136, NW-Verlag, Bremerhaven, 2006 |
| Böhm, A.; Murtz, B.; Sommer, C.; Wermuth, M. | “Location-Based Ticketing in Public Transport,” in: Proceedings of the 8th International IEEE Conference on Intelligent Transportation Systems, Springer-Verlag, Berlin, Heidelberg, 2005 |
| Sommer, C.; Wermuth, M.; Wulff, S. | “Why Do Travelers Choose This Exact Route?—Recording Travel Routes and Motives for Route Selection,” in: TU Dresden, 20th Transportation Science Days, Conference Proceedings, Dresden, 2005 |
| Sommer, C. | “Is Public Transit Running Out of Passengers?”, in: DER NAHVERKEHR, Issue 5, pp. 8–11, Alba Fachverlag, Düsseldorf, 2005 |
| Sommer, C. | “Public Transit in an Aging Society,” in: DER NAHVERKEHR, Issue 4, pp. 14–19, Alba Fachverlag, Düsseldorf, 2005 |
| Wermuth, M.; Sommer, C.; Mayer-Kreitz, M. | “The Use of New Technologies to Collect Data on Individual Travel Behavior,” in: DVWG, Internationales Verkehrswesen, Issue 12, Deutscher Verkehrs-Verlag, Hamburg, 2005 |
| Sommer, C.; Firl, K. | “Improving the Reporting Process in the ADAC Traffic Jam Reporting Service Through the Use of Mobile Communications Technologies,” in: Straßenverkehrstechnik, Issue 5, Kirschbaum-Verlag, Bonn, 2004 |
| Sommer, C.; Wermuth, M. | “Mobile Applications Based on GSM Location Tracking and IVR Systems,” in: Center for Transportation at the Technical University of Braunschweig, IMA 2004—Information Systems for Mobile Applications, Braunschweig, 2004 |
| Sommer, C.; Wulff, S. | “Benefits and Acceptance of Location-Based, Mobile-Phone-Supported Schedule Information Services,” in: TU Dresden, 19th Transportation Science Days, Conference Proceedings, Dresden, 2003 |
| Wermuth, M.; Sommer, C.; Kreitz, M. | “Impact of New Technologies in Travel Surveys,” in: Jones, P.; Stopher, P., *Transport Survey Quality and Innovation*, Pergamon, Oxford, 2003 |
| Sommer, C. | “Measuring Travel Behavior Using Mobile Phone Technology: Concept, Validity, and Acceptance of a New Survey Method,” in: TU Braunschweig, Series of the Institute for Transportation and Urban Planning, Vol. 51, Shaker Verlag, Aachen, 2002 |
| Sommer, C. | “Telematics-Based Method for Surveying Traffic Behavior,” in: Research Association for Road and Transportation Engineering, Heureka 2002—Optimization in Traffic and Transportation, FGSV-Verlag, Cologne, 2002 |
| Sommer, C.; Wulff, S. | “Location- and Person-Based Mobility Services in Public Transit,” in: Center for Transportation at the Technical University of Braunschweig, IMA 2002—Information Systems for Mobile Applications, VDE Verlag GmbH, Berlin, 2002 |
| Sommer, C. | “TTS (TeleTravel System)—A Telematics System for the Automatic Recording of Traffic Behavior,” in: Heinickel, G.; Dienel, H.-L., Mobility and Traffic Research—A Comparison of Recent Empirical Methods, ZTG Series, TU Berlin, Berlin, 2001 |
| Sommer, C.; Wermuth, M.; Wulff, S. | “Tele Travel Systems (TTS)—A Telematic System for the Automatic Survey of Travel Behavior,” in: Proceedings of the 9th IFAC Symposium on Control in Transportation Systems, pp. 198–205, Braunschweig, 2000 |
| Sommer, C. | “Disco Buses in Rural Areas,” in: DER NAHVERKEHR, Issue 7–8, Alba Fachverlag, Düsseldorf, 1999 |
| Sommer, C.; Breiting, T.; Menzel, K. | “Information System ‘Cost-Effective and Ecological Housing Construction,’” in: VDI, VDI Progress Reports Series 4: No. 140, pp. 16–23, VDI-Verlag GmbH, Düsseldorf, 1997 |
| Sommer, C.; Breiting, T.; Menzel, K. | “Facility Management of Administrative Buildings,” in: VDI, VDI Progress Reports Series 4: No. 135, pp. 167–172, VDI-Verlag GmbH, Düsseldorf, 1996 |
| Sommer, C.; Menzel, K. | “Quality Control in Reinforced Concrete Construction Using Virtual Reality,” in: VDI, VDI Progress Reports Series 20: No. 173, pp. 103–109, VDI-Verlag GmbH, Düsseldorf, 1995 |