Investigating the effects of intersection control types on emissions using microsimulation models and field measurements
Bibliographic record
Abstract
Emission estimates are becoming critical metrics to evaluate the impacts of transportation projects such as modifications of the road geometry, updating of intersection signalization or technological improvements.To evaluate the impact of projects and policies, methods to evaluate emissions related to climate change and public health (through metrics such as air quality) have become more prevalent.The general objective of this research is to determine the impact of traffic controls, in particular stop signs, in comparison to other intersection controls, on vehicular emissions.More specifically, the objective of the first project is to propose a microscopic modelling approach based on emission software tools to evaluate the impact on emission levels before and after the transformation of one-way stop to all-way stop intersections in an urban corridor.This case study used the EPA's emissions model MOVES, along with the traffic microsimulation model VISSIM, to evaluate the emissions impact of intersection modifications using a Montreal case study.Intersections in the network of interest were converted from one-way stop controlled to all-way stop controlled in a political move aimed at improving pedestrian and cyclist safety.This modification was analysed using the models and it was found that energy consumption as well as emission rates of CO, NOx, NO, NO2, atmospheric CO2, PM10 -exhaust, PM10 -brake-wear, PM2.5 -exhaust, and PM2.5 -brake-wear increased after the stop signs were added, with growth range of 4.4% to 32%.The only pollutants whose rates decreased were PM2.5 and PM10 due to tire-wear.In the second portion of the research, a PEMS device was used with several test vehicles.These vehicles were driven throughout the network which was tested in the first portion of this research, along with several networks of a similar composition.Data was sorted based on type of intersection and compared.Results showed that within a 30m buffer of the intersection, a general pattern exists where intersections with stop in the minor approach generate the least emissions, followed by all-way stop intersections, then signalized intersections with emissions increases of approximately 50% and 20% between the types respectively.However, this pattern disappears when data is controlled for the number of seconds a vehicle spends within each type of intersections, with emission rates becoming relatively equal.Furthermore, the trajectories of these experiments were entered into MOVES in order to compare the model's predictions to the ground-truth data that was collected.It was found that MOVES estimates were inconsistent, with Résumé L'estimation des émissions est en voie de devenir un indicateur clé à l'évaluation des impacts engendrés par des projets de transport tels que les modifications à la géométrie des chaussées, la mise à jour de la signalisation routière aux intersections ou l'apport d'améliorations technologiques.Pour évaluer l'impact des projets et des politiques, plusieurs méthodes d'estimation des émissions portant sur le changement climatique et la santé publique sont devenues plus répandues (au travers de critères tels que la qualité de l'air).L'objectif général de cette recherche est de déterminer l'impact des contrôles de la circulation, en particulier les panneaux d'arrêt, sur les émissions des véhicules, comparativement à d'autres contrôles aux intersections.De façon plus spécifique, l'objectif du premier projet est de proposer une approche de modélisation microscopique basée sur des outils informatiques pour évaluer l'impact, sur les niveaux d'émission dans un corridor urbain, avant et après la transformation des intersections contrôlées par des panneaux d'arrêt unidirectionnel à celles dotées de panneaux d'arrêt « toutes directions ».Cette étude de cas a utilisé le modèle d'émissions MOVES de l'EPA, ainsi que le modèle de micro simulation de la circulation VISSIM, pour évaluer l'impact des modifications des intersections sur les émissions à l'aide d'une étude de cas basée à Montréal.Les intersections se trouvant dans la zone d'étude ont été réaménagées en passant d'un arrêt unidirectionnel à un arrêt « toutes directions » dans le cadre d'une décision politique visant à améliorer la sécurité des piétons et des cyclistes.Cette modification a été évaluée à l'aide des modèles susmentionnés et il en ressort que la consommation énergétique ainsi que les taux d'émission de CO, NOX, NO, NO2, CO2 atmosphérique, PM10 -gaz d'échappement, PM10 -usure des freins, PM2,5 -gaz d'échappement et PM2,5 -l'usure des freins ont augmenté à la suite de l'installation des panneaux d'arrêt, avec une hausse variant de 4,4% à 32%.Les seuls polluants dont les taux ont diminué étaient les PM2,5 et les PM10 en raison de l'usure des pneus.Dans la deuxième partie de la recherche, un dispositif PEMS a été utilisé avec plusieurs véhicules d'essai.Ces véhicules ont parcouru l'ensemble du réseau qui figure dans la première partie de cette recherche, ainsi que plusieurs autres réseaux de composition similaire.Les données ont été classées en fonction du type d'intersection et ont ensuite été comparées.Les résultats ont démontré qu'à l'intérieur d'une zone tampon de 30 m de l'intersection, on y retrouve une tendance générale avec laquelle les intersections contrôlées par un panneau d'arrêt dansTable of Contents
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".