# Urban Congestion Avoidance Methodology Based on Vehicular Traffic Thresholding
## 3 Vehicular Traffic Congestion Avoidance Methodology
By integrating the proposed vehicular traffic thresholding mechanism into the route computation algorithm from SUMO, this paper reports the following achievements:

* Using the proposed congestion avoidance solution (CAVTTM), we simulated 26 vehicular traffic scenarios that ran on a comprehensive set of road network topologies in four urban areas: Barcelona, Bucharest, New York and Tokyo;
* Generated moderate and high traffic congestion by running between 50 K+ and 100 K vehicles for each simulation and reaching up to 49 K concurrent vehicles that run on a road network topology at a specific moment;
* Through the vehicular traffic thresholding mechanism, for the scenarios with 100 K+ vehicles, we reduced the time spent in traffic by more than 32% and CO\({}_{2}\) emissions by more than 31%, whereas, for the scenarios with 50 K+ vehicles, we reduced the time spent in traffic by more than 69% and CO\({}_{2}\) emissions with more than 61%;
* Using a vehicular traffic thresholding mechanism, we balanced traffic in Barcelona to improve the number of simulated vehicles in free flow by 200%;
* The proposed CAVTTM is an effective, scalable and reliable solution to traffic congestion that can be used in most road network topologies. A noteworthy work for the future is to introduce into CAVTTM routes that are not generated using the vehicular traffic thresholding mechanism but are generated in an individualistic manner (e.g., fastest routes at a specific moment) and to observe the evolution of the entire vehicular context. From a more practical perspective, for further work, we can focus on officially integrating the proposed vehicular traffic thresholding mechanism in the SUMO's route computation algorithm so that the community can benefit from simulated routes that balance traffic and avoid congestion. Furthermore, it would be very valuable to integrate the proposed vehicular traffic thresholding mechanism in the field, by adapting the route computation algorithm of an existing navigation solution to use the thresholding levels and KEP tree to model traffic data. When used by users in a specific urban area, such a solution can provide valuable traffic data to be evaluated. This study is limited to predicting and avoiding vehicular traffic congestion in the context of large-scale simulated vehicular traffic on a comprehensive set of road network topologies. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Solution** & \(\mathbf{t_{total}}\)\% & \(\mathbf{Fuel_{total}}\)\% & \(\mathbf{CO_{2}}\)\% \\ \hline CAVTTM & **69** & **61** & **61** \\ \hline FOXS [45] & 2.6 & N/A & N/A \\ \hline SOPHIA [46] & 15 & N/A & 25.95 \\ \hline Re-RouTE [47] & 65 & N/A & N/A \\ \hline Stan [8] & 2.6 & N / A & N/A \\ \hline Elouni [50] & 41 & 20 & N/A \\ \hline Chunjiang [51] & 31 & N/A & N/A \\ \hline CAC [52] & 48.3 & N/A & N/A \\ \hline \hline \end{tabular} N/A: not applicable.

\end{table} 
Table 14: Comparison of vehicular traffic congestion reduction solutions. **Author Contributions:** Conceptualization, I.S., D.A.G., P.I.D. and R.P. ; methodology, I.S., D.A.G., P.I.D. and R.P. ; software, I.S., D.A.G., P.I.D. and R.P. ; validation, I.S., D.A.G., P.I.D. and R.P. ; formal analysis, I.S., D.A.G., P.I.D. and R.P. ; investigation, I.S., D.A.G., P.I.D. and R.P. ; resources, I.S., D.A.G., P.I.D. and R.P. ; data curation, I.S., D.A.G., P.I.D. and R.P. ; writing--original draft preparation, I.S., D.A.G., P.I.D. and R.P. ; writing--review and editing, I.S., D.A.G., P.I.D. and R.P. ; visualization, I.S., D.A.G., P.I.D. and R.P. ; supervision, I.S. and R.P. ; project administration, I.S. and R.P. All authors have read and agreed to the published version of the manuscript. This research received no external funding. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The data presented in this study are available on request from the corresponding author. **Conflicts of Interest:** The authors declare no conflict of interest.