Understanding and assessing demand-responsive public transport
How can demand-responsive transport improve public transport provision, and how can we assess its contribution? These questions have been central to our work over the past two and a half years.
On 21 October 2026, we presented the findings of our research project at BBSR in Bonn and discussed them with experts from public administration, research and transport practice. The final event brought the project to a successful close and provided an opportunity to explore how demand-responsive transport can develop further.
A diverse landscape of services
From conventional shared taxi services booked by phone to digitally bookable on-demand shuttles, demand-responsive transport complements public transport, particularly where fixed-route services reach their limits. These services connect sparsely populated areas, provide early-morning and late-evening connections, and bring passengers to bus and rail services. However, existing assessments of public transport provision often capture them only partially, as they largely rely on fixed stops and timetable data.
This was the starting point for the research project “Nationwide overview and assessment of demand-responsive transport services compared with conventional fixed-route public transport”. The aim was to map services across Germany, examine their use and acceptance, and develop a methodology to assess their contribution to public transport accessibility.
Rupprecht Consult and TRAPICO carried out the project from April 2024 to October 2026 under the “Region gestalten” programme, commissioned by BMWSB and BBSR.
We combined a nationwide inventory with in-depth studies of twelve practical examples. Interviews, expert discussions and workshops provided insights into success factors and challenges. Building on these findings, we developed two assessment models, which were tested and refined through four case studies.
589 services serving different purposes
The inventory identified 589 demand-responsive transport services across 375 of Germany’s 400 districts and independent cities (based on the 2025 analysis). Demand-responsive transport is therefore already widespread. Conventional services and those closely aligned with fixed routes continue to dominate, while flexible, digitally managed services make up a significant but smaller share.
Most of the services identified fulfil a public service role, ensuring mobility where regular fixed-route services leave gaps in geographical coverage or operating hours. Only around 5% are so-called “on-top” services, operating alongside regular public transport primarily to offer greater convenience.
Another key finding concerns data. While basic service information is often available, standardised operational and quality data are missing in many places. Requirements to provide these data should therefore be incorporated into procurement and contract design from the outset.
A methodology for comparing service quality
The methodology provides a basis for assessing demand-responsive transport services both against one another and in relation to fixed-route services. It builds on the Austrian public transport quality classification model, extending it to reflect the specific characteristics of demand-responsive transport. The first model assesses temporal and spatial coverage and can be applied even where data are limited. The second incorporates additional quality criteria, including actual service availability, waiting times, detours, surcharges and accessibility for people with disabilities.
Context is essential. A dial-a-ride bus providing basic services for journeys planned in advance serves a different purpose from an area-wide on-demand shuttle that can be booked at short notice. Assessments must therefore always be considered alongside the service’s purpose, its geographical context and the available data.
The methodology offers practical value. It can provide a regional or nationwide picture of demand-responsive transport provision and support comparisons between services. For transport authorities and operators, it is also a useful tool for regularly reviewing service quality and identifying opportunities for improvement. At the same time, it makes the contribution of demand-responsive transport clearer to the public and policymakers, supporting informed decisions about introducing, adapting or continuing services.
The long-term contribution of demand-responsive transport
The closing discussion focused on long-term funding, the prospects for autonomous driving and integration with fixed-route services. There was also particular interest in how impacts on accessibility and social participation could be measured more effectively in future.
Our conclusion: demand-responsive transport can close important gaps in provision when its role is clearly defined and it is fully integrated into the public transport system. The project findings provide a foundation for planning, assessment and further development.
The final report, including the findings, assessment methodology and recommendations for action, is available on the project website: Nationwide overview and assessment of demand-responsive transport services compared with conventional fixed-route public transport
We warmly thank BBSR, our project partner TRAPICO, and all participating transport operators, transport authorities, state-level bodies and experts for their close collaboration, practical insights and constructive discussions.
