Showing papers by "Max Donath published in 2006"

Vehicle Positioning System Using Location Codes in Passive Tags

Abstract: Vehicles driving on a roadway interrogate passive tags in or on lanes of the roadway. Codes in the tags represent locations along the highway and which lane the vehicle is traveling in. Units in the vehicles communicate longitudinal and lane positions derived from the codes among each other or with infrastructure units for purposes such as traffic management, alerts concerning other vehicles, alerts concerning external conditions, or traffic control. The units may also communicate vehicle lengths or other parameters or characteristics. Vehicle units may communicate with sensors and actuators in the vehicles for purposes such as updating the vehicles' positions between adjacent tags. Specific applications for intelligent transportation systems are described.

The Minnesota Mobile Intersection Surveillance System

Abstract: Detailed crash analyses indicate that poor gap selection, rather than stop sign violation, is the primary causal factor in crashes at rural, unsignalized intersections. To determine under what conditions the gap selection process fails, a transportable rural intersection surveillance system has been designed and implemented. The system can be installed at any rural intersection, and can be used to collect data regarding the gap acceptance behavior of drivers at the rural intersection. Described herein is the design and performance of the transportable rural intersection surveillance system. This system will be deployed at eight rural intersections in eight US states, from April 2006 through December 2008. Data collected by the system will be used to determine whether regional differences in gap acceptance behavior exist. If differences exist, they will be quantified and used in the design of an intersection decision support system, a device under development designed to assist a driver at a rural intersection with the gap selection process

Road bank angle considerations in modeling and tilt stability controller design for narrow commuter vehicles

Abstract: Narrow tilting vehicles that occupy a half width lane can play a big role in addressing traffic congestion problems by effectively doubling the capacity of existing highway lanes. In designing the tilt stability control system of such a vehicle consideration of the road bank angle is crucial since it plays a big role in minimizing the torque requirement of the tilt actuation system. In this paper the dynamic model of a tilting vehicle that takes into account the road bank angle is first developed. Then the design of a direct tilt control scheme that stabilizes the tilt mode of such a vehicle is outlined. Since the controller designed makes use of current road bank angle data, a method is outlined on how to determine the road bank angle from accelerometer readings. Finally simulation results are presented and discussion of the results is given.

Development of internet-based traffic simulation framework for transportation education and training

Abstract: Many traffic simulation software packages are available to help traffic engineers and researchers study and evaluate the potential impact of proposed traffic management strategies and policies. However, the existing tools require a significant investment in time to learn how to create models, perform calibrations, and, finally, analyze the results. This substantial learning curve severely restricts their application and makes it difficult for engineering students, the general public, and policy makers to take advantage of these tools. An Internet-based traffic simulation framework was developed to enhance the learning experience for transportation students and engineers. Pregenerated traffic scenarios were first implemented as part of an undergraduate civil engineering class. An interactive simulation tool was developed to allow users to make changes to the model and examine the impacts on traffic. This now allows students, for example, to minimize the queue length at the traffic signal by changing the cycle length or splits. This interactive traffic simulation tool was deployed and tested in an undergraduate class of 73 students. Feedback was collected from the instructors and the students and will lead to additional enhancements of the laboratory module. This web-based traffic simulation framework can also incorporate larger road networks that allow one to consider a multiplicity of traffic management strategies, thus providing a valuable tool for educating and training transportation professionals.

An evaluation of a lane support system for bus rapid transit on narrow shoulders and the relation to bus driver mental workload

Abstract: The use of dedicated bus shoulders is a key method for implementing bus rapid transit (BRT) in areas that do not have the space for additional infrastructure. However, the narrow width of the bus shoulder and the need to anticipate traffic hazards in the adjacent lane can both be significant stressors for bus drivers. Bus driver mental workload and stress in response to these conditions should be a significant concern both for operational safety and driver health. This pilot study evaluated the potential stressors of traffic density and shoulder width in the context of an express BRT service in a large US metropolitan area. In addition, the study considered the potential role of a prototype lane support system (LSS) to support vehicle control within the narrow shoulder boundaries. Ten experienced bus drivers drove an actual route with an instrumented bus equipped with and without LSS. Self-reported effort was recorded along with performance measures of speed and position control relevant to mobility and safety objectives. Bus drivers did note stressors in the BRT environment and the prototype LSS. However, the use of the shoulder during high-density traffic conditions did improve mobility. Moreover, the LSS did enhance safety on the shoulder when there was high-density traffic in the adjacent lane. However, there was no evidence that the LSS reduced bus driver workload while operating in the narrow shoulder. Future research should consider the impact of BRT operations and support systems on bus driver mental workload and stress, and support the deployment of such devices for bus operations on shoulders during high traffic volumes.

Rural Expressway Intersection Surveillance for Intersection Decision Support System

Abstract: More than 30% of all vehicle crashes in the United States occur at intersections; these crashes result in nearly 9,000 annual fatalities, or approximately 25% of all traffic fatalities. Moreover, these crashes lead to approximately 1.5 million injuries per year, accounting for approximately 50% of all traffic injuries. In rural Minnesota, approximately one-third of all crashes occur at intersections. AASHTO recognized the significance of rural intersection crashes in its 1998 Strategic Highway Safety Plan and identified the development and use of new technologies as a key initiative to address the problem of intersection crashes. A study of 3,700 rural Minnesota intersections showed that right-angle crashes account for 36% of all rural intersection crashes. Approximately 50% of crashes at intersections that have higher than expected crash rates are right-angle crashes. Further investigation also found that poor gap selection is the predominant causal factor in these crashes. To address the problem of poor...

Vehicle position system using passive roadway tags

Abstract: Vehicles driving on a roadway interrogate passive tags in or on lanes of the roadway. Codes in the tags represent locations along the highway and which lane the vehicle is traveling in. Units in the vehicles communicate longitudinal and lane positions derived from the codes among each other or with infrastructure units for purposes such as traffic management, alerts concerning other vehicles, alerts concerning external conditions, or traffic control. The units may also communicate vehicle lengths or other parameters or characteristics. Vehicle units may communicate with sensors and actuators in the vehicles for purposes such as updating the vehicles' positions between adjacent tags. Specific applications for intelligent transportation systems are described.