Due to the advanced spatial data collection technologies, the locations of vehicles on roads are now being collected nationwide, so there is a demand for applying a micro-level emission calculation methods to estimate regional and national emissions. However, it is difficult to apply this method due to the low data collection rate and the complicated calculation procedure. To solve these problems, this study proposes a vehicle trajectory extraction method for estimating micro-level vehicle emissions using massive GPS data. We extracted vehicle trajectories from the GPS data to estimate the emission factors for each link at a specific time period. Vehicle trajectory data was divided into several groups through a k-means clustering method, in which the ratios of each operating mode were used as variables for clustering similar vehicle trajectories. The results showed that the proposed method has an acceptable accuracy in estimating emissions. Furthermore, it was also confirmed that the estimated emission factors appropriately reflected the driving characteristics of links. If the proposed method were utilized to update the link-based micro-level emission factors using continuously accumulated trajectory data for the road network, it would be possible to efficiently calculate the regional- or national-level emissions only using traffic volume.

A practical method is presented for systematically evaluating the network impacts of advanced traveler information systems (ATISs) to support well-informed project decisions and well-founded funding priorities. Detailed comparative assessments of available evaluation tools are given on the basis of a common set of desirable criteria. A mesoscopic network modeling and dynamic traffic assignment (DTA) tool, namely, DYNASMART-P, was identified as a promising candidate model and was applied to the evaluation of case study scenarios in a subnetwork of the Triangle Regional Model in North Carolina. The case study involved planned work zone activities occurring during nonpeak time periods. The case study demonstrated that the DYNASMART-P DTA tool is capable of providing reasonable evaluation results, including realistic estimates of the effectiveness of ATISs in mitigating the congestion caused by work zone activities. The case study analyses further illustrated the high value of traveler information through an example benefit–cost analysis based on the scenario modeling. The simulation results were validated for reasonableness through comparison with field speed data. Finally, several potential DTA functionality enhancements are identified that will further support ATIS evaluation.

This paper describes the design and implementation of a simulation code supplement to a commercial microsimulation system that makes efficient use of traffic information data that can be disseminated via wireless vehicular ad hoc networks. The transmitted information elicits timely responses to driver behavior for speed or path changes in a realistic way. A simulation model developed by following the prescribed design was used in a case study application to simulate vehicle dynamic route diversion and variable speed limits following a severe incident in a small network. Simulation results indicate that the model results are sensitive both to different market penetration levels of vehicles equipped with wireless communications capabilities and to various control strategies, which therefore gives credibility to the utility of the system design.

PURPOSES :The purpose of this study is to check the possibilities of traffic pattern analysis using MatSIM for urban road network operation in incident case. METHODS : RESULTS :The simulation results and the actual measured values are similar. The simulation results show reasonable ranges which can be used for traffic pattern analysis. CONCLUSIONS :The change of traffic pattern including trip distribution, traffic volumes and speeds according to various incident scenarios can be used for traffic control policy decision to provide effective operation of urban road network. individual behavior model, MatSIM, activity based model, stochastic dynamic, incident Keywords

Traffic simulation models have been used for assessing various transportation strategies. Through comparing results from a simulation model and real field data, researchers try to show how close the model can reproduce the real world traffic. This model verification step is one of the most essential tasks in modeling procedure. Traffic counts and speeds have been frequently used for the verification or validation. Authors modeled severe PM peak bottleneck situation on the I-40 corridor in Raleigh, North Carolina using DYNASMART-P, a mesoscopic traffic simulation tool and verified the model. NCDOT has Traffic Information Management System which has archive capability for the traffic speeds on the I-40 corridor. However, the authors selected travel time as the field measure for model verification and collected the data using a GPS equipment because the speed data from NCDOT speed detectors are spot speeds which are not appropriate for comparison with link average speed from the simulation model. This paper describes the GPS field data collection procedure, the model verification method, and the results.