Trucks and trucking

This Technical Summary pertains to Report 2023-29, “Identifying and Optimizing Electric Vehicle Corridor Charging Infrastructure for Medium- and Heavy-Duty Trucks,” published June 2023.

This project studies the benefits and barriers of increased adoption of medium-duty and heavy-duty electric trucks, referred to as e-trucks, and presents a methodology for optimizing the location of e-truck charging stations in Minnesota. In general, e-trucks provide zero tailpipe emissions and lower operating and maintenance costs. However, some barriers to adopting e-trucks include higher initial purchase costs, lack of charging and maintenance infrastructure, limited range, and charging time. The methods presented in this study aim to address the charging infrastructure planning, which provides information about e-truck charging activities, changes in vehicle miles traveled (VMT), and potential operating cost savings.

This Phase II study involved studying the short-term and long-term effects of the Compliance Review (CR) programs conducted in the Region 5 states of Wisconsin, Indiana, Michigan, Minnesota, Ohio, and Illinois on the Out-of-Service (OOS) rates of interstate freight-carriers based in those states. A preliminary analysis of the inspections data revealed low OSS rates based on inspection records--across all level of inspection--for the years 1993-94, indicating defective collection/interpretation of data and thereby invalidating any OOS rate analysis for this time period. Also, it was found that Level 1 and 2 inspections together constitute nearly 80 percent of all inspections records, thus marginalizing the effect of the other levels of inspection on the final results of this analysis. The results of both the short-term and long-term effects of OOS rate analysis suggest an overall positive effect of the Compliance Review program on the reduction of OOS (Event and Violation) rates of the carriers. These results are consistent over the rest of the time period (1995-97) and across three levels of inspection (Levels 1, 2, and 3). The conclusions drawn about the nature of the effects of a Compliance Review could be much better validated if the currently spurious inspections data for the years 1993-94 were restored, or a fresh analysis using later available data (1997-99) were carried out based on the same algorithms.

In this project, researchers sent mail surveys to commercial vehicle operators (CVOs)--for-hire carriers and private fleet operations-in the Twin Cities to determine their use of congestion information and their ability to attach specific values to congestion costs. The project also assessed the ability of CVOs to avoid congestion. The report presents survey findings. Despite the fact that a vast majority of respondents indicated congestion information would be useful, CVOs do not rely currently on available congestion information to any significant extent. The reasons may include lack of awareness and/or an inability of CVOs to effectively use the form and content of the information. For-hire carriers also are not well-equipped to estimate congestion costs with any degree of confidence. This results from apparently inadequate costing systems and/or technology to capture costs at the vehicle level. Further, respondents said that they had very little flexibility to adjust schedules to avoid congestion. Also, shippers without private fleets feel significantly less strongly about congestion as a problem than their counterparts with such fleets. Thus carriers maybe constrained in their ability to use congestion information. The report also contains a demographic profile of CVOs operating in the Twin Cities and recommendations for further research.

This report summarizes the work performed during the 18-month period ending in December 1997. Researchers investigated the use of differential global positioning systems (GPS), inertial measurement, and other sensing technologies as the basis of a system that would prevent crashes. Such a system attempts to control the vehicle if it leaves the lane because the driver is incapacitated. The report includes in its appendices related work on driver fatigue and a bibliography on the effect of drugs and alcohol on driving behavior. The long-term goal of this research involves development of a "driver-centered" vehicle control system capable of providing lane-keeping feedback to the driver, and, if necessary, of imposing aggressive intervention strategies to take over control of the vehicle, steer it to a safe position on the shoulder, and stop it. This research also targets the development of "driver assistive" technologies--such as Heads Up Display and torque feedback supplied by the steering wheel--which provide information to the driver without necessarily requiring computer control of the vehicle. The highlight achievement during this funding period has been the successful demonstration of a GPS-based automated lane-keeping mode of a tractor-trailer on the Minnesota Road Research Project (Mn/ROAD) test track. The report concludes with a strategy for pursuing future deployment.

The SAFETRUCK program focuses on preventing accidents on rural highways, especially those associated with run-off-the-road incidents and driver fatigue, by giving the vehicle the ability to steer to the side of the road and come to a safe stop if the driver falls asleep or is otherwise incapacitated. Researchers have equipped a Navistar 9400 series class 8 truck tractor with the sensors and control computers necessary to perform this task. Designing the controller that will steer the truck requires a mathematical model of the lateral response of the truck to steering inputs. In this project, researchers developed a lateral dynamic model by incorporating second order dynamics into the steering axle tires. Simulation of the resulting models indicated dynamic behavior that was close to the experimental data for speeds between 15 and 30 miles per hour. This is the first time that a lateral dynamic model of a truck has been experimentally verified. Both models, however, resulted in experimentally determined values for steering axle cornering stiffness that were considerably smaller than published values for the Goodyear G 159 tires on the truck.

This study seeks to measure the safety performance of compliance reviews (CRs) conducted in Minnesota under the Motor Carrier Safety Assistance Program (MCSAP). This study employs data gathered by the Federal Highway Administration surrounding two MCSAP activities: compliance reviews and roadside inspections. It specifically investigates the change in a carrier's annual out-of-service violation rate (OOS) in response to receiving a review or a higher number of inspections. A measurable reduction in a carrier's OOS rate occurs in the year after a CR, according to the data. The annual OOS rate appears to be a viable measure of the impact of a compliance review, given that a carrier's vehicles and drivers are adequately inspected in the year following a CR.

A computer program based on statistics and signal process theory was developed to automatically detect peaks and valleys from sensor response signals obtained during live heavy truck and falling-weight deflectometer testing. Statistics are applied to each signal to characterize the nature of the response signal and to make the detection of maxima and minima more efficient. Noise effects are treated by applying filtering techniques including Fast Fourier Transform and time domain filtering. The Procedure was found to work effectively and is now being used to process pavement response data that has been collected at the Minnesota Road Research Project (Mn/ROAD) over the past three years. The output file from the program is readily loaded into the Mn/ROAD database.

In October 1994, the Minnesota Department of Transportation's (Mn/DOT) Office of Motor Carrier Services sponsored nine focus groups of small shippers and motor carriers to learn more about how federal initiatives affect Minnesota's transportation community. The focus groups revealed several common issues that affect both carriers and shippers, including the following: low awareness of government agencies, services, and functions; perceived inconsistency in the application of rules and regulations; shippers' reliance on motor carriers as a source of information; inconsistent standards of loss and damage claims; and confusion of application of safety hazards. In addition to identifying perceptions about expected changes due to federal preemption of state motor carrier regulation, the research also provided insights into other timely concerns of shippers, motor carriers, and insurance companies. The report also includes recommendations in the areas of information, research, and education.

This photo includes automobiles, river barges, trains, and an airplane, with downtown St. Paul in the background.