Evaluation of the environmental impact of intelligent transportation systems on congested roads.

摘要

The deployment of Advanced Traveler Information System (ATIS) has as an objective to reduce congestion levels in specific corridors by rerouting drivers to less congested routes. The level of benefit depends on the original level of congestion and the level of confidence that drivers would have in the system. The main focus of ATIS is to improve the network performance by reducing traveling times, queue lengths, and collisions among others. The implementation of ATIS also has environmental impacts due to changes in travel speeds, traffic flows, and distance travel.;To calculate the quantity of emissions, an instantaneous emission model was developed by using second-by-second real world emission data. Finally, this methodology combines both analyses, emission model and traffic analysis, to quantify the impact on emissions that the ATIS could produce on a congested network.;The findings of this research showed the benefits of using the disaggregated approach to calculating emissions. It was found that average variables are not necessarily appropriate to represent sudden changes on speed and acceleration that can be present on a link due to the changes on vehicular flow. Emissions models that are based on instantaneous variables demand large amount of experimental data due to the impossibility of controlling the experimental settings. The final result showed that the use of a disaggregated approach to calculate emissions can be applied in small scale projects where a high level of detail is needed.;This research is focused on using a different approach to quantify the emission changes when an ATIS is applied, and give a spatial distribution of those changes along the links. This approach used disaggregated traffic variables, instead of aggregated variables, to characterize the changes from transportation and environmental point of view. The application of an ATIS was simulated using microsimulation techniques and its impact was analyzed by comparing instantaneous speed and acceleration in various points along the main links.