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U of MNUniversity of Minnesota
Center for Transportation Studies


Seminar Series – Fall 2001

October 2

(Rescheduled from Sept. 18)

"Orientation and Navigation in Elderly Drivers"

Herbert Pick
Institute of Child Development, Selma de Ridder, Kinesiology and Leisure Studies

Seminar Article

It is well known that older drivers have a higher accident rate than younger post adolescent drivers. There are a variety of possible reasons for this. One, which we have been investigating, is the possibility that older drivers are distracted from vehicle operation by allocation of attention to wayfinding and staying oriented. In our studies we have tried to ascertain whether there are age differences in knowledge of spatial layout after drivers have learned a new route. Results indicate there are such age differences and it seems likely that there are also gender differences. These studies have been carried out both in the real driving situation and in a driving simulator.

October 9

"The Effect of Intelligent Cruise Control Vehicles in Mixed Traffic on the Environment and Traffic Flow Characteristics"

Petros Ioannou
University of Southern California, Department of Electrical Engineering Systems

Seminar Article

The deployment of vehicles with the ability to follow each other automatically in the longitudinal direction is a reality. In Japan, Europe and more recently in the US, several car manufacturers are developing vehicles with an intelligent cruise control (ICC) system as an option.ICC or adaptive cruise control as it is often referred to is designed to allow automation in the longitudinal direction, while the driver remains responsible for lateral control and emergencies. The ICC vehicles are designed to respond to other vehicle disturbances in a smooth way and maintain a tight vehicle following spacing at steady or during smooth maneuvers. In this talk we will analyze the effect of ICC vehicles in traffic that involves manually driven vehicles. We will show analytically and demonstrate via simulations and experiments with actual vehicles that the ICC vehicles act as 'filters' by attenuating high frequency disturbances generated by manually driven vehicles. This characteristic of the ICC vehicles is shown to have beneficial effects on pollution and fuel economy. In this talk we will quantify these benefits using simulation results and actual experiments. Since most pollution generation and fuel consumption take place during transients, the effect of the ICC vehicles is considered to be a significant one.

October 16

"Simpson's Paradox, Measurement Error, and Ecological Fallacies in the Speed Versus Safety Debate"

Gary Davis
Civil Engineering

Seminar Article

Repeal of the National Maximum Speed Limit, allowing the states to set speed limits above 55 mph, has re-energized the debate about the relationships between speed limits, vehicle speeds, and likelihood of a crash. The variety of claims found in this debate are at least partially due to methodological problems in earlier studies. This seminar will identify three classic methodological flaws and show how they contribute to the current confusion.

October 30

"Effects of Advanced Warning Flashers at Signalized Intersections on Simulated Driving Performance"

Tom Smith
Kinesiology and Leisure Studies

Seminar Article

This study carried out a human factors analysis of the effects of advanced warning flashers (AWFs) on simulated driving performance, during interaction by drivers with simulated signalized intersections, as they traversed one of four different simulated driving task environments (SDTEs) that featured: (1) a total distance of 11.3 mi; (2) AWFs present (test) or not present (control) at every intersection; (3) low (50 mph - LSL) or high (65 mph - HSL) speed limit; (4) 10 intersections per SDTE; (5) 2 intersections per SDTE assigned to one of 5 vehicle-proximity-to-yellow (VPTY) levels: all green, and 0, 2, 3.5, and 5 sec. Results indicate that AWFs tend to slow vehicle speeds and acceleration, and increase braking, for test compared with control trials, effects more pronounced for LSL compared with HSL trials. Results also point to two groups of Ss with distinctly different driving behaviors during test trials, with Ss in one group showing more cautious, and those in the other more risk- taking, behavior during interaction with AWF intersections. This finding suggests that it may be unrealistic to expect AWFs to influence the behavior of all drivers in a consistently beneficial way during driver-signal interactions.

November 13

"Networks and Places: New Hierarchies in Access and Activities"

Lee Munnich, Tom Horan, and Ken Keller
Humphrey Institute of Public
David Levinson
Civil Engineering

Seminar Article

The discussion will examine a series of studies being undertaken by the Humphrey Institute addressing the growth of networks. Projects discussed will include: 1) the relationship of social/employment networks and transportation use, 2) the spatial and economic impacts of urban and rural high-tech networks on land use, 3) management challenges to inter-organizational transportation/emergency services network, and 4) the growth of a traffic networks based on the present conditions of the network, traffic demand, other demographic characteristics, project costs, and a budget constraint. Crosscutting themes of policy issues in dealing with complex networks will be touched on in the discussion.

November 27

"The Use of Range Sensors in ITS Applications"

Alec Gorjestani
Mechanical Engineering

Seminar Article

The Intelligent Vehicles Laboratory (IVL) at the University of Minnesota has been performing research with range sensors since 1996. This seminar will describe the lab's research using laser and radar based sensing technologies in Intelligent Transportation Systems (ITS). The results of sensor evaluation experiments will be presented in which probe vehicles equipped with Differential Global Positioning Systems were used to validate system specifications. A description of the applications of range sensing in ITS will also be given. Specifically, the IVL's research on driver displays, collisions avoidance, and advanced false target rejection techniques will be discussed.

December 11

"Can Advances in Vehicle Technologies Provide Solutions to Highway Congestion?"

Rajesh Rajamani
Mechanical Engineering

Traffic congestion in the country’s major metropolitan areas continues to grow every year. Annual increases in traffic demand continue to outpace increase in highway capacity making it unlikely that roadway expansion can provide a solution to highway congestion. This talk looks at how advances in vehicle-based technologies could provide an evolutionary solution to the problem. Adaptive cruise control (ACC) systems are being developed by many automotive manufacturers and are likely to become standard automotive equipment in the future. The first part of this talk describes how the development of intelligent algorithms on ACC vehicles can lead to an increase in highway capacity while at the same time ensuring safe highway travel. Next, the talk describes how the enhancement of ACC systems with co-operative vehicle-highway infrastructure can lead to dramatic increases in highway capacity. The final part of the talk discusses the development of a new class of narrow vehicles that provide a completely different approach towards addressing the traffic congestion issue. A prototype narrow vehicle with automatic tilt control has been developed at the University of Minnesota. Results will be presented from a research project focused on making this narrow vehicle as safe, comfortable and easy to drive as a regular passenger sedan.