Quantifying the implementation impacts of a point to point automated urban shuttle service in a large-scale network

Autonomous point to point shuttles are an emerging paradigm of a future mobility-on-demand ecosystem. However, the traffic and environmental impacts of their operation are largely under researched especially in relation to influential infrastructure related factors and service-related specifications.

The scope of this study is to reveal the factors that may affect the degree and magnitude of the road segment level impacts of an autonomous urban shuttle service (AUSS) operating in a city using microsimulation and structural equation modeling (SEM). For the purposes of this research, a systematic framework is developed and applied in the city center of Athens (Greece), which encompasses different scenarios of operations including: (i) Baseline (no AUSS operation), (ii) AUSS operation with a dedicated lane during peak hour, (iii) AUSS operation mixed with regular traffic during peak hour and (iv) AUSS operation mixed with regular traffic during off-peak hour. Two connected automated vehicle (CAV) profiles were used to model the advent of automation in the overall traffic: a cautious profile is introduced first, followed by a more aggressive profile. SEM findings indicate that the AUSS operation has a significant effect on cumulative travel time per segment and CO2 emissions per segment only during the scenario of mixed operation with traffic during off-peak hours. Additionally, the influence of the network geometry is correlated with reduced travel time and with increased CO2 emissions. Road traffic density was found to be positively correlated with both travel time and CO2 emissions, while the penetration of both cautious and aggressive CAVs was found to be negatively correlated with both indicators.

Read our publication ‘Quantifying the implementation impacts of a point to point automated urban shuttle service in a large-scale network’ based on the research carried out in WP5 in the Transport Policy Journal using this link.

LEVITATE participation in the ICTR conference, Rhodes, 2021

Authors: Apostolos Ziakopoulos (NTUA), Maria Oikonomou (NTUA), Julia Roussou (NTUA), George Yannis (NTUA)

  1. General information

The Hellenic Institute of Transportation Engineers (HITE) and the Hellenic Institute of Transport (HIT/CERTH) co-organized the 10th International Congress on Transportation Research (ICTR 2021), which was held on September 1st – 3rd 2021, at the Mediterranean Hotel in Rhodes, Greece. The spotlight theme of the 2021 Congress was “Future Mobility and Resilient Transport: Transition to innovation” (https://ictr.gr/). LEVITATE was represented in the conference by NTUA (https://www.nrso.ntua.gr/).

  1. CCAM workshop – Challenges & Lessons learned,
    Wednesday, September 1st, 2021, (09:00 – 13:30).

The Conference started with a series of workshops, one of which was devoted to CCAM, titled Challenges & Lessons Learned in CCAM, organized by SHOW Innovation Action (https://show-project.eu/) and in specific by the Technical Management team of the Hellenic Institute of Transport (HIT) of CERTH. There were 12 presentations made – some of which originated from regular papers of the Conference and some of which being invited speeches – whereas the workshop closed with a round table. The work presented originated from SPACE, SHOW, AVENUE, WISE-ACT, Drive2theFuture, Trustonomy, SUaaVE, ICT4CART, EIMANTRA, LEVITATE, SPROUT and ARCADE initiatives as well as from CCAM Platform WG3.

NTUA represented LEVITATE actively in the CCAM workshop (i) with a presentation by Apostolos Ziakopoulos titled “Forecasting and backcasting of Connected Automated Vehicle impacts using multiple methodological inputs” (ii) with the participation and contributions of Professor George Yannis to the roundtable discussion of eight renowned experts.

Critical outcomes of the presentation include the reality that the integration of the expectations of different users (City/road management authorities, researchers, industrial practitioners) in a functional Policy Support Tool remains an uphill battle. Furthermore, backcasting capabilities for impact assessment provide a powerful means to complement forecasting and to define visions & goals to be reached. Large degrees of uncertainty remain for the CCAM landscape regarding the scope, form & feasibility of automation-based policy interventions. The combination of multiple methodologies for CCAM impact assessment brings considerable advantages (increased parameter coverage) but is hard to integrate different variable dependencies and requires high level coordination.

  1. Session II (A) – Intelligent Transport Systems,
    Thursday, September 2nd, 2021, (14:30 – 16:30).

Session II (A) Advanced Intelligent Transport systems can improve current transportation systems both for passenger and freight. For the successful implementation of ITS in real conditions, it is critical to gather and combine different types of data (infrastructure-based, real time traffic data, as well as other open-source, dynamic or static data). Overall, CAVs are considered as a promising solution towards the improvement of the current traffic conditions. However, several simulation studies presented at this session indicated that no significant differences in terms of traffic-related parameters are expected. In addition, the level of improvement is critically affected by the proportion of traffic operated by CAVs (mixed traffic vs whole traffic operated with AVs).

NTUA represented LEVITATE in the session with a presentation by Maria Oikonomou titled “Impacts of autonomous transit services on urban networks: The case of Athens, Greece”, focusing on the microsimulation work conducted within WP5 of LEVITATE.

Key outputs of the presentation include the findings regarding point-to-point shuttle bus services, which led to increased delays and total distance travelled, while on the contrary the on-demand service showed decreased delays and constant driven kilometers. The introduction of the different shuttle bus services did not significantly affect conflicts as well as emissions, which were significantly lower when the number of CAVs was increased. In a small-scale urban network, automation did not affect traffic-related measurements, while in a large-scale urban network decreased delays, increased distance travelled and reduced conflicts were noticed.

  1. Session IV(A) – Transport planning and policy,
    Friday, September 3rd, 2021, (08:30 – 10:15).

Session IV(A) – Transport planning and policy addressed crucial issues examined and presented by expert researchers for the development and implementation of specific policies, tools and actions for achieving a successful transport planning in urban areas. As well established, sustainability plays an important role in all fields of transportation systems, thus it has to be seriously considered from the very beginning of a transport planning process. Therefore, actions and policies to be implemented should always be evaluated, leading researchers in the development and application of appropriate tools for achieving the best results in terms of sustainability.

NTUA represented LEVITATE in the session with a presentation by Apostolos Ziakopoulos titled “Forecasting impacts of Connected and Automated Transport Systems within the Levitate project.” This presentation placed more emphasis on the forecasting estimator of LEVITATE compared to the workshop presentation.

Several conclusions considered the future of the PST development, and the functionalities which will be available for the PST user as the LEVITATE project moves forward. Overall, it was highlighted that the LEVITATE PST aspires to become the go to, one stop shop tool for the calculation of societal impacts of automation by experts, authorities, stakeholders and any other interested party.

  1. Concluding remarks

As stated in the roundtable discussion of the CCAM workshop, and in the sessions co-influenced by LEVITATE inputs, CCAM initiatives should include holistic new paradigms that have to satisfy sustainable mobility while achieving transport safety, efficiency and environmental targets simultaneously. Stakeholder cooperation is essential to reach solutions satisfying the needs of road users, citizens, researchers, industry and authorities, and to achieve more clear and transparent outcomes.

Despite the projected elimination of human-related errors from automation, CCAM should not be treated as a de-facto substitute to conventional transport, but rather, a competitor that will have to strive hard for public acceptance. Public transport is proposed as a priority field for CCAM deployment due to both increased societal needs and levels of technological readiness.

  1. References relevant to the LEVITATE participation in ICTR 2021:
  • Ziakopoulos A., Roussou J., Boghani H., Hu B., Zach M., Veisten K., Hartveit K.J., Oikonomou M., Vlahogianni E., Thomas P., Yannis G. (2021). “Forecasting impacts of Connected and Automated Transport Systems within the Levitate project.” 10th International Congress on Transportation Research (ICTR) 2021, Rhodes, Greece, 2-3 September 2021.
  • Oikonomou M., Mourtakos V., Roussou J., Ziakopoulos A., Vlahogianni E., Yannis G. (2021). “Impacts of autonomous transit services on urban networks: The case of Athens, Greece”. 10th International Congress on Transportation Research (ICTR) 2021, Rhodes, Greece, 2-3 September 2021.

All NTUA presentations in ICTR 2021 are available online: https://www.nrso.ntua.gr/ictr2021-10th-international-congress-on-transportation-research-september-2021/

Watch now: webinar on policy interventions

This LEVITATE webinar provided insights on the potential impacts of introducing policy measures related to on-street parking repurposing (driving or cycle lane, public space or pick-up/drop off), road-user pricing and dedicated CAV lanes. These policy interventions have been assessed using realistic traffic models (Manchester and Leicester) in terms of their impacts on traffic (delay and travel time), the environment (CO2, NOx and PM) and road safety. A variety of traffic assessment methods have been used including micro and mesoscopic simulation, systems dynamics and Delphi. A fully calibrated traffic model for Vienna was also presented.

The LEVITATE webinar ‘Policy interventions’ took place on 18 October 2021. Listen to researchers from Loughborough University and the Austrian Institute of Technology.
Watch the recording here »

Road safety impacts of Connected and Automated Vehicles

Connected and automated transport systems (CATS) are expected to be introduced in increasing numbers over the next decades. Moreover, they are expected to have considerable impacts on mobility, safety, the environment and society as a whole. One of the aims of LEVITATE is to forecast these impacts. This article collects the impact of CATS on road safety which has been briefly presented during the last webinar of LEVITATE, as well. Moreover, the article written by Wendy Weijermars (SWOV), Andreas Hula (AIT), Amna Chaudhry (LOUGH), Sasa Sha (LOUGH), Rins de Zwart (SWOV), Celina Mons (SWOV) and Hitesh Boghani (LOUGH) further presents the specific impacts on road safety for the individual sub-use cases and communicates how these expected impacts can be quantified. Conclusions suggest that in normal circumstances, CAVs are expected to have a lower crash rate than human driven vehicles; CAVs make less errors than human drivers, are assumed to respect all traffic rules and are expected to have lower reaction times and less variability in driving behaviour.

Curious about further conclusions drawn in the article? Read the entire article: LEVITATE: Road safety impacts of Connected and Automated Vehicles.
Note: This article has been updated in July 2021 including further research results derived from the sub-use case.

LEVITATE: applying mesoscopic activity chain simulation

The present article focusses on the application of an agent-based mobility simulation model for the city of Vienna which utilizes activity chain descriptions of the simulated agent’s daily objectives. This is done in the context of the goals of project LEVITATE.

It entails a brief description of the model method, the specific  features of the model, the expectable and intended output of the model, its general assumptions as well as detailsmon two specific areas of interest within the project objectives, namely automated urban transport and road use pricing.

LEVITATE webinar on road safety assessment of CATS

On 27 May, the 4th LEVITATE webinar took place with more than 80 participants to share the project’s research results about the impact of automated vehicles on road safety.

The interactive webinar was introduced by Andrew Morris (Loughborough University) who shared general information about Levitate with the audience. The webinar was moderated by Wendy Weijermars (SWOV) while Rins de Zwart (SWOV), Amna Chaudry (Loughborough University) and Andreas Hula (AIT) shared their research results on road safety impacts of connected and automated vehicles (CATS). Based on a poll launched during the webinar, most participants expect a considerable improvement in road safety with the introduction of CATS, but they do not expect that all serious crashes can be prevented. LEVITATE’s two-steps approach in the estimation of impacts determines that which ways the road safety is impacted by the development of CATS, and as a second step, the project tries to quantify these impacts as far as possible with the help of literature review and conducting interviews with stakeholders. The audience was proactive and asked several questions to the panelists which has been answered live or written during the event.

Curious about the presented impacts on road safety and the outcomes of the discussion? Watch the recorded webinar here:

Delphi method to measure impacts of automated vehicles

The Delphi method is a process used to arrive at a collective, aggregate group opinion or decision by surveying a panel of experts. This concept was developed by the RAND Corporation for the military in order to forecast the effects of new military technology on the future of warfare, and then continued to make multiple practical applications of this method (Dalkey & Helmer, 1963). The Delphi methodology is based on a repetitive interview process in which the respondent can review his or her initial answers and thus change the overall information on each topic (Hsu & Sandford, 2007). This presupposes that the participants will be willing to not only give answers on the topics but also to repeat the interview in possibly more than two cycles.

Within LEVITATE, the Delphi method is used to determine all impacts that cannot be defined by the other quantitative methods (traffic microsimulation/system dynamics). Initially, a long list of experts were identified for each use case, and contacted via an introductory mail asking them to express the willingness of participation. Those who responded positively (70 experts) participated in the main Delphi process.

If you want to know more about the Delphi studies conducted in the frame of Levitate, including the list of impacts and result introduction to the Policy Support Tool, read our article from the National Technical University of Athens.

LEVITATE participates in 3rd annual meeting of Robomobile Life

The 3rd annual meeting of the Robomobile Life initiative will take place on 19 and 20 May to explore the role that local authorities (cities, regions) can play in steering the emergence and evolution of automated mobility. LEVITATE will contribute to this workshop along with the Polis secretariat.

Initiated by the French Ministry for Ecological Transition in 2017, the “robomobile life” series of  foresight workshops aims to foster thinking, exploration, questioning, reflection and debate on all subjects and matters related to robomobility. The workshops seek to create a better understanding of the key issues and long-term choices that decision-makers from both the public and private sectors may have to deal with in the coming years and decades, here in France and abroad.

The decade 2021-2030 could see the deployment of the first transport services provided by automated vehicles. This implementation will be gradual, targeted and regulated and should be driven by genuine use cases that meet mobility needs that are poorly or insufficiently covered by the existing offer. These first stages of putting transport automation into service in real conditions will be decisive.

  • To what extent can a city choose the robomobile model that suits it best?
  • What influence will local/regional government stakeholders have on the different socio-technical models associated with automation?
  • What will be the the rules of the game and who will set them?

This third annual meeting aims to provide reflection on these questions. This event has been designed to give participants the possibility to compose their own tailor-made programme. The sessions are independent of each other. An English-speaking track is open to all international attendants and all plenaries will be translated from French to English.


For further information and to register »

Monetary impacts of connected and automated vehicles

Deliverable D3.3 of LEVITATE deals with converting impacts of connected and automated vehicles to monetary terms. Converting impacts to monetary terms is needed to include them in cost-benefit analyses.

One of the objectives of LEVITATE is to develop a tool for performing cost-benefit analyses of policies designed to maximise the societal benefits of introducing connected and automated vehicles. This tool will be part of the Policy Support Tool developed by LEVITATE. Can everything be converted into monetary terms when it comes to the impact of automated vehicles?

Read Rune Elvik’s article from the Norwegian Institute of Transport Economics »


Backcasting city dialogues: Feasible paths of interventions – the case of Vienna

The impact of connected and automated transport systems (CATS) in several areas also has strong implications on a very central question of urban development: Given a certain vision based on a set of quantified policy goals for a city or a region, which supporting role take recommended policy interventions related to CATS to achieve that vision? This article provides a short overview of the backcasting approach applied in LEVITATE that addresses this question.

From a cities’ perspective the advent of connected and automated vehicles (CAVs) is not a strategic goal by itself. Rather, they are welcome if they are able to contribute to the defined smart city goals and have to support a livable city. Improvements in road safety or reductions in the demand for public parking space are promising candidates for such supported goals, with quantitative investigation of impacts currently ongoing in the project. But there are some other impact areas where an increasing market penetration of CAVs (without specific regulations) might be in conflict with the strategic goals of a city: empty AVs avoiding parking fees might increase congestion; the attractiveness of AVs might lead to adverse changes in modal split; acceptance of longer driving distances (due to increased comfort and use of travel time for working) might further increase road traffic and promote urban sprawl. It is therefore essential for cities to integrate the full spectrum of related policy interventions into their considerations to prepare for the era of CATS – right from the start. Some positive impacts might be reinforced and accelerated by the appropriate policies, other desired impacts might occur only if a specific combination of policy interventions is applied – with the appropriate timing – and finally, some unwanted negative impacts might be mitigated by corresponding interventions. These causal relationships, however, are not always as simple and intuitive as it might appear at first sight. A lot of interdependencies – as in every complex system extending over different domains – makes it a necessity to apply a formal approach and consider a set of different methodologies that can support cities in their strategic decisions.

Defining a desirable vision in a quantitative way is the essential starting point for the backcasting process. From that vision the idea is to work backwards, via influencing factors (that are impacting the goals and indicators of the vision), to policy interventions which address these factors and thereby contribute towards the vision. Generating this series of logical links is a central part of the process, as it highlights feasible paths of interventions, steering into the desired direction. The steps in this process are explained in more detail and exemplified for the City of Vienna in the following article by the Austrian Institute of Technology.