Cross-cutting Issues

A common method of Dilemma zone (DZ) protection at isolated intersections is to hold the green until the number of vehicles in DZ is lower than a threshold number. Since the threshold number is empirical and fixed, it cannot accommodate the dynamic and time-varying traffic patterns and therefore have to be adjusted regularly. This paper presents a new Markov-process-based DZ protection algorithm, which considers each time step, the algorithm first predicts the future states with the Markov state-transit matrix then compare them with the current state to determine whether to end the green or not. As a result, the new end-green criterion is determined not by the fixed threshold values but by the current state and the Markov state-transit matrix. Meanwhile, the Markov matrix is automatically updated when the new observed detected state transitions come in. The simulation results showed that the new algorithm maintains reliable and effective protection in a dynamic traffic environment. At last, we present an evaluation of the new algorithm performance using two methods of calculating the current state: low-fidelity prediction with advance detectors and high-fidelity prediction with future Connected Vehicles Technologies.

University of Kentucky

Virginia Polytechnic Institute and State University

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

This paper presents a new approach for processing vehicle trajectories collected from the field. Unlike traditional approaches such as Finite Differencing or Locally Weighed Regression, the proposed approach combines bi-level optimization with spline interpolations, seeking to minimize not only measurement errors, but also internal inconsistency errors in positions, speeds and accelerations data. Real-life vehicle trajectories collected from I-94 WB were used to test the proposed approach. Results indicate the new approach is effective in eliminating both measurement and inconsistency errors. Moreover, the proposed approach is further compared to Locally Weighted Regression, an approach that has been commonly used in earlier studies, by conducting a sensitivity analysis where the magnitude of measurement errors is varied with different values. The comparison results show that the proposed approach is not only more robust with respect to varying measurement errors, but also more effective in removing data inconsistency from vehicle speed and acceleration profiles.

KLD Associates Inc.

Minnesota Traffic Observatory

Presented at the ITS America Annual Conference and Exposition, November 16-20, 2008, New York, New York

During  the  last  decade,  in-vehicle  route  guidance  systems  have  known  a  significant  spread. These systems, apart from providing assistance to drivers, offer the chance to manage traffic in  such  a  way  that  allows  an  increase  in  road  network  capacity  and  therefore  a  decrease  in traffic congestion, without the high cost expansion of the road infrastructure. In this paper, we propose  the  application  of  the  basic  principles  of  the  Constrained  System  Optimal  model, used  to  solve  the  traffic  assignment  problem,  in  the  case  of  routing  a  single  vehicle.  In contrast to the User Optimal model that provides no traffic improvement  guarantees and the System Optimal model that is unrealistic, the Constrained System Optimal solution adopts the goal of reducing congestion and at the same time remaining fair for drivers when selecting a route.

University of Patras

Presented at the ITS America Annual Conference and Exposition,November 16-20, 2008, New York, New York

The Connected Vehicle for Safety, Mobility and User Fee Project is an extensive demonstration project undertaken in parallel with other Connected Vehicle Programs.  MnDOT’s efforts include designing, building and testing three new software applications to be run on an existing in-vehicle aftermarket consumer device that combine safety and mobility applications from the Connected Vehicle world with a mileage-based user fee application from the road user pricing world.  As part of this project, an extensive review of commercial-off-the-shelf (COTS) navigation devices was conducted to determine the strengths and weaknesses of each platform for meeting the system requirements of the project.  This presentation will summarize the findings from that review and evaluation.

Battelle

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

The Connected Vehicle for Safety, Mobility and User Fee Project is an extensive demonstration project undertaken in parallel with other Connected Vehicle Programs.  MnDOT’s efforts include designing, building and testing three new software applications to be run on an existing in-vehicle aftermarket consumer device that combine safety and mobility applications from the Connected Vehicle world with a mileage-based user fee application from the road user pricing world.  As part of this project, an extensive review of commercial-off-the-shelf (COTS) navigation devices was conducted to determine the strengths and weaknesses of each platform for meeting the system requirements of the project.  This presentation will summarize the findings from that review and evaluation.

Author: Robert Zimmer, CSEP

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida