Speaker:

Dr. Satish Gupta, Professor, Department of Soil, Water, and Climate, University of Minnesota

Description:

Water Retention refers to the relationship between the amount of soil water and the energy with which it is held. This relationship is important for characterizing the rate at which water moves through a granular material under both saturated and unsaturated conditions. Important consequences of this relationship are the amount of drainage that may occur through soils, how deep the frost might penetrate, and how strength properties vary seasonally. Pavements are constructed on compacted soils that are typically unsaturated. Several design and maintenance measures are undertaken to maintain unsaturated conditions in the pavement because they provide favorable engineering soil properties. However, the conventional procedures for pavement design are often based on empirical procedures and not on unsaturated soil mechanics principles. The goal of this project is to develop a pavement design method that is consistent with Mn/DOT and AASHTO mechanistic-empirical design framework but is based on the principles of unsaturated soil mechanics. Specifically, we propose to predict shear strength and modulus of unbound pavement materials using index tests, soil water characteristics curves, and simple mechanical tests.

Speaker:

Dr. Alfred Marcus, Professor, Department of Strategic Management and Organization, University of Minnesota

Description:

Hybrid electric vehicles offer the potential for substantial increases in the fuel efficiency of U.S. vehicles. They could mitigate persistent and serious environmental problems, improve our economic and national security, and reduce trade imbalances. The question, however, is whether hybrid technology will reach its potential. Can it solve the problems brought on by oil dependence without changes in behavior, markets, and government policies? Marcus will argue that technology by itself without changes in these other factors can only take us so far. Without attention to these factors, he says, hybrids are more hype than hope.

Speaker:

Dr. John Gulliver, Department of Civil Engineering, University of Minnesota

Description:

Many technologies have been developed to treat runoff and remove suspended and dissolved contaminants, many technologies have been developed. These include grassed swales, filter strips, detention ponds, grit chambers, infiltration trenches, and sand filters. The advantages of sand filters include their high removal rates, adaptability to low infiltration soils, and their small space requirements, making them suitable for urban areas. While the removal rates and costs of the other technologies have been well reported, data on sand filters, especially enhanced sand filters which can contain layers of peat, limestone, topsoil and/or other media, remains limited. This research investigates the effectiveness and associated costs of the aforementioned technologies, giving a cost-effectiveness analysis on each method. The research also investigates enhanced sand filtration as a means of treating storm water runoff. The final result is a set of guidelines that enable practicing engineers to select and design the most cost-effective treatment option for a given project.

Speaker:

Dr. Gary Davis, Associate Professor, Department of Civil Engineering, University of Minnesota

Description:

In recent years increased attention has been given to predicting the effects of roadway improvements on traffic safety. Tools have been developed in cooperation with the Federal Highway Administration and the Transportation Research Board that attempt to predict crash experience; these tools require estimates of crash modification factors (CMF) to produce predicted reduction benefits. The tools make use of empirical Bayes statistics, which currently require that crash data be overdispersed. This research illustrates an alternative method for estimating CMFs that can be applied whether the crash data are overdispersed or not. The method combines the hierarchical Bayes model with a model that allows for temporal changes in the covariates. The method was used to compute estimates for the CMFs associated with signalizing or changing the left-turn phasing of sets of non-rural intersections. This research was especially interested in the effect on left-turn crashes. Marginally significant results included: signalization does not produce a definite effect on major left-turn crashes; phase-changes on the major approaches from permitted/protected to protected phasing decrease major approach left-turn crashes; and phase-changes on the minor approaches from permitted to permitted/protected do not significantly affect the minor approach left-turn crashes.

Speaker:

Kate Sanderson, URS Corporation and Ph.D. student in the Department of Civil Engineering at the University of Minnesota

Description:

What would it take to build our way out of congestion in the Twin Cities?" was the question posed by researchers five years ago. This previous study solved a roads-only network design problem (NDP) for the Twin Cities of Minnesota. Building on that work, another network design problem is examined for the Twin Cities metropolitan area of 3 million to examine the tradeoff between demand side reductions and limited access capacity expansion necessary to achieve desired levels of service. The problem is simplified by pre-determining a mode split, which allows for incorporating decreasing demand directly as an input rather than in the model formulation. The problem is solved using Sequential Linear Expansion (SLIE), a modified method of successive averages (MSA). Computation time for the large network is decreased to a reasonable length using another modification, the MSA with decreasing re-initialization (MSADR). A typical personal computer can solve this large-sized problem within 24 hours. For forecasted travel demand for 2030, it was found that if the number of trips were reduced by 20%, lane-miles needed to achieve LOS D decreases by 43%.

Speaker:

Dr. Dan Halvorsen, Physiologist, University of Minnesota Medical School and ExMed Clinic

Description:

Walking and biking may solve two societal problems:

1. childhood and adult obesity trends
2. fossil fuel costs, supply, and efficiency

One solution for obesity is to increase daily exercise patterns. By looking
closely at daily destinations, it is often possible to include in the
exercise prescription a daily walk or bike ride. If this walk or bike ride
complements daily destinations, there is a 67.2% adherence rate.

When the walking and biking routes are efficient, safe, fun, and easily
accessible, the adherence is 81.4%. This suggests that our transportation
systems can be enhanced by providing more effective walking and biking
options. Doing so could have positive effects on obesity trends and energy use.

Contact:

Paul Bergson

Location:

2525 4th St SE
Minneapolis, MN 55455
Map

Speaker:

Max Donath, Director, ITS Institute and Professor, Department of Mechanical Engineering

Description:

The State of Minnesota and the University of Minnesota have participated in the stop sign gap assistance portion of the USDOT's Intersection Decision Support effort and the Cooperative Intersection Collision Avoidance Systems effort. Minnesota's work included analyzing crash data from Minnesota intersections and establishing a test intersection for evaluating sensors and for data collection. The University of Minnesota team installed surveillance equipment at the test intersection and recorded driver gap selection behavior under various conditions. A human factors evaluation tested the viability of several concepts for signs that could be installed to provide gap assistance information to the driver. The effort has now been expanded to become a cooperative system where using wireless communications, the vehicle and the infrastructure work together to provide enhanced assistance to the driver.