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Evaluation of Cooperative Intelligent Transport Systems Time to Red and Time to Green according to various Key Performance Indicators

Spanjer, W.B. (2022) Evaluation of Cooperative Intelligent Transport Systems Time to Red and Time to Green according to various Key Performance Indicators.

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Abstract:This study assesses the effects when Cooperative Intelligent Transport Systems (hereafter: C-ITS) Time to Green and Time to Red are implemented. This assessment contains different aspects, namely environment, safety, efficiency, and driver comfort. When a driver uses Time to Green and Time to Red, he or she knows how many seconds a certain traffic light remains red or green. By researching these implementations, it can be determined whether this brings advantages or (more) dangerous situations. Real-life experiments with these applications have also been carried out, but these often took place in a small environment with a low penetration rate. During such a real-life experiment, many external factors can occur that cannot be taken into account. This makes it difficult to draw a proper conclusion about the findings. When the implementation takes place in a micro-simulation, this is not the case. The research has been done in a microscopic program, PTV VISSIM. The implementation of the C-ITS applications was made possible by writing an external piece of code and linking it to this program. This code checks if the traffic light approaching vehicle is a C-ITS vehicle. If this is the case, the vehicle will be informed how long the traffic light will remain red (i.e. Time to Green) or how long it will remain green (i.e. Time to Red). With this information, appropriate measures can be taken. In the case of a Time to Red vehicle, different scenarios can arise. For example, when the traffic light will be green for a longer time. Because of this the C-ITS vehicles do not get a different speed and drive at their own desired speed on. It can also be that the traffic light is almost red. If it is doubtful whether the vehicle can drive through the green light, the speed will be increased to 60 km/h. This speed will be maintained for as long as necessary. This means that once it is certain that the vehicle can drive through the green light anyway, the speed will be reduced to the old desired speed. It may also be the case that the vehicle has to stop anyway because the travel time to the traffic light is too long and the time that the traffic light has a green light is too short. In this case, the required speed will be reduced to 20 km/h. This speed is chosen to simulate the throttle release. PTV VISSIM does not offer this itself. The latter situation may also occur in the case of Time to Green. In this case, the traffic light is on red longer than the travel time to the traffic light. The last scenario that can happen is that it is almost green. In this case, the desired speed is temporarily decreased to 20 km/h. As soon as the traffic light turns green again, the vehicle will return to the old desired speed. The results of the model contain 11 different variants. The first variant is when no C-ITS is applied, the base measurement. In each subsequent variant, the number of C-ITS users increases by 10%. This process happens until there are 100% C-ITS users in the network. For the assessment of the model, four KPIs have been set up. These serve to check whether the implementation of Time to Red and Time to Green brings a benefit or not. These KPIs are environment, safety, efficiency, and driver comfort. Each KPI is linked to one or more outcomes of the model. For example, the environment has acceleration and deceleration, safety has the speed differences between sequential vehicles, efficiency has the average speed, stop delay, average queue length, and travel time, and finally, driver comfort has the number of stops of a vehicle. The analysis of the results shows that the implementation of the C-ITS applications has different advantages and disadvantages. Positive effects can be seen regarding safety, environment, and a part of efficiency (average queue length). The negative speed differences between sequential vehicles decrease. For the environment, it can be seen that vehicles generally accelerate less and brake more slowly. The part of efficiency that shows positive results is the average queue length, which generally decreases considerably. Questionable results are also shown for driver comfort and part of efficiency (stop delay). For driver comfort, it can be seen that the driver has to stop less often, which is a positive result. Only this does not apply to right-turning traffic. They do not have to use the traffic light and thus the C-ITS application, but they are (much) hindered by it. The same becomes clear from the results of the stop delay. Also here, the vehicles that turn right are hindered by the C-ITS application. Finally, there are also negative results for the last two efficiency outcomes, namely average speed and travel time. The average speed generally decreases, and the average travel time increases.
Item Type:Essay (Bachelor)
Faculty:ET: Engineering Technology
Programme:Civil Engineering BSc (56952)
Link to this item:https://purl.utwente.nl/essays/93016
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