Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - TransAID (Transition Areas for Infrastructure-Assisted Driving)

Teaser

As the introduction of automated vehicles becomes feasible, even in urban areas, it is necessary to investigate their impacts on traffic safety and efficiency. This is particularly true during the early stages of market introduction, where automated vehicles of all SAE levels...

Summary

As the introduction of automated vehicles becomes feasible, even in urban areas, it is necessary to investigate their impacts on traffic safety and efficiency. This is particularly true during the early stages of market introduction, where automated vehicles of all SAE levels, connected vehicles (able to communicate via V2X), and conventional vehicles share the same roads with varying penetration rates.
There will be areas and situations on the roads where high automation can be granted, and others where it is not allowed or not possible due to missing sensor inputs, high complexity situations, etc. At the border of such areas many automated vehicles will change their level of automation. We refer to these areas as “Transition Areas”. It is very likely that Transition Areas will have a negative impact on traffic safety and efficiency, since transitions of control may fail or lead to non-optimal behavior.
TransAID develops and demonstrates traffic management procedures and protocols to enable smooth coexistence of automated, connected, and conventional vehicles, especially at Transition Areas. A hierarchical approach is followed where control actions are implemented at different layers including centralized traffic management, infrastructure, and vehicles.
To achieve this, a first step is the modelling of the existing and upcoming automation functionalities and driver behavior. This is a mandatory step to get insights not only into current situations, but also to predict the future impact. Therefore, the models are used to perform simulations in different shares and scenarios. As result, there is measurable impact. By following the hierarchical approach, infrastructure-assisted management solutions are investigated and simulated advising connected, automated, and conventional vehicles at Transition Areas, taking into account traffic safety and efficiency metrics. As cooperation between infrastructure and connected/automated vehicles is a key requirement, communication protocols are developed. Measures to detect and inform conventional vehicles are also addressed.
The most promising solutions are then implemented as real world prototypes and demonstrated under real urban conditions. TransAID is going to prototypically implement the results on real infrastructure hardware to show the general feasibility of the management solution.
Finally, guidelines for advanced infrastructure-assisted driving are formulated. These guidelines also include a roadmap defining activities and needed upgrades of road infrastructure in the upcoming fifteen years in order to guarantee a smooth coexistence of conventional, connected, and automated vehicles.

Work performed

TransAID started by investigating future automation functionalities and system behavior, focusing on automation limits. It turned out very soon that this task is very challenging, as future automated driving systems are very often described in a glamorous way, without giving too much detail about the weaknesses. This is esp. true for OEMs describing their future mobility concepts. On the other hand, existing automation functionalities, abilities and weaknesses can be found in the internet at several places, but very often not analyzed in a scientific way, as this would require internal knowledge about the system which is often not available. Research projects dealing with future automation systems are also quite rare, making a scientific approach to the question quite difficult. In addition, finding a specific weakness of a specific system should not be the goal of the project, since the most likely solution for this will be an update of the vehicle automation system solving the weakness. All of this led to the idea that TransAID is investigating services which allow vehicles to solve situations which they cannot handle on their own, classified by the types of problem and service. E.g. in case a vehicle is not able to follow a given route without braking rules, infrastructure may suggest a way to overcome the obstacle. In case a vehicle needs to perform a minimum risk maneuver when the handover of control to the driver fails, infrastructure may suggest a good position for coming to a safe stop. In total, five different categories have been identified.
TransAID now investigates scenarios inside the five categories in two project iterations.
As a first step of the first iteration, the general behavior of automated vehicles has been modelled. This includes models for longitudinal and lateral control of the vehicles including lane changes, and a model for transition of control to the driver. Simulations using the simulation platform SUMO have been performed showing the impact of automated vehicles on the traffic in Transition Areas without any countermeasure.
As a next step, the identified service use cases have been implemented in simulation, including the traffic management algorithm and the communication protocols and message sets. The latter has been done in line with current V2X standardization activities and does also include measures to detect and advice conventional vehicles, e.g. by using variable message signs.
In order to allow precise simulations, the already existing iTetris simulation platform has been chosen as basis, which allows coupling of SUMO simulations with the ns-3 communication simulator. This platform has been used to simulate the first project iteration’s use cases.
Currently, the proposed traffic management measures are implemented in real world prototypes, while in parallel the use cases and scenarios for the second project iteration have been defined.

Final results

As mentioned, future automated driving capabilities and weaknesses are not yet well known. Nevertheless, TransAID found traffic management measures which will be able to help automated vehicles in the future in case a locally bound problem occurs leading to a transition of control or a situation which cannot be handled by the automated vehicles alone.
Although the exact kind of problem an automated vehicle may have in the future can only be guessed, it is very important to address solutions for general and very likely problems already very early, which is pioneered by TransAID. Changing the perspective from the inside, just being passenger of an automated vehicle enjoying the increase of comfort, to the outside, where the behavior of other automated vehicles impacts the traffic safety and efficiency of all vehicles is unavoidable. This is especially true when looking at Transition Areas where negative impacts are very likely. By following this approach, TransAID offers solutions for future mobility issues caused by automated vehicles. This includes the early standardization of solutions (e.g. V2X message sets), the early response of stakeholders, etc. – mandatory steps for future smooth coexistence of conventional and automated vehicles.

Website & more info

More info: https://www.transaid.eu/.