Road tests of alertness variables. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Time and distance in acceleration of road commercial vehicles

The time and the distance traveled during the acceleration and the velocity retaking are parameters used for the comparison and the project of vehicles. In this paper equations for the calculation of those parameters are presented. Several criteria are presented for the shift gears. It is also verified the occurrence or not of total slip during the acceleration of the vehicle. The theoretical models were implemented in a developed computational system. Such system was applied in a Mercedes-Benz do Brazil sample vehicle, in order to facilitate comparisons between the simulate values and the experimental road tests. Copyright © 1997 Society of Automotive Engineers, Inc.

Measurement of Ice Scraping Forces on Snow-Plow Underbody Blades, HR-372, 1997

In this study, several new cutting edges for removal of ice from the roadway were tested in a series of closed road tests. These new cutting edges consisted of a variety of serrated shapes. The study also included measurement of ice scraping forces by in-service trucks. These trucks were instrumented in a similar manner as the truck used in the closed-road tests. Results from the closed-road and in-service tests were analyzed by two parameters. The first parameter is the scraping effectiveness, which is defined as the average horizontal force experienced by a cutting edge. The amount of ice scraped from the roadway is directly proportional to the magnitude of the scraping effectiveness. Thus an increase in scraping effectiveness indicates an increase in the amount of ice being scraped from the roadway. The second parameter is force angle, which is defined as tan to the -1 power [vertical force/horizontal force]. A combination of a minimal force angle and a maximized scraping effectiveness represents a case in which the maximal amount of ice is being removed from the pavement without an exceptionally large vertical force. Results indicate that each cutting edge produced a maximal scraping effectiveness with a testing configuration of a 15 deg blade angle and a 23,000 lb. download force. Results also indicate that each cutting edge produced a minimal force angle with a testing configuration of a 15 deg blade angle and a 10,000 lb. download force. Results from the in-service trucks produced similar data and also similar trends within the data when compared to the results of the closed-road tests. This result is most important, as it suggests that the closed-road tests do provide an accurate measure of ice scraping forces for a given blade and configuration of that blade. Thus if the closed-road tests indicate that certain blades perform well, there is now excellent reason to conduct full scale tests of such blades.

Standardized electrical tests for electrical equipment in road vehicles Case: Visedo Oy PowerMASTER M-frame

Electrical road vehicles were common at the begin of the 20th century but internal combustion engines took a victory from electrical motors in road vehicles. The acknowledgement of the environment, and the price and the availability of the crude oil are reasons for the comeback of the electrical vehicles. Advancement in industrial technology and political atmosphere in EU as the directive 20--20--20, which consists of reducing fossil emission, increasing renewable energy and increasing the energy efficiency, have made the electrification popular again. In this thesis tests based on standard ISO 16750--2 electrical loads for electrical equipment in road vehicles are made for Visedo Oy's PowerMASTER M-frame power electronics device. This device is designed for mainly drive trains in mobile work machines and marine vessels but can be used in other application in its power range which also includes road vehicles. The functionality of the device is tested with preliminary tests which act as a framework for the tests based on standards.

Ventilation and FFFS fire tests for “Calle 30” road tunnels

Between 2003 and 2007 an urban network or road tunnels with a total constructed tubes length of 45 km was built in the city of Madrid. This amazing engineering work, known as "Calle 30 Project" counted with different kinds of tunnel typologies and ventilation systems. Due to the length of the tunnels and the impact of the work itself, the tunnels were endowed with a great variety of installations to provide the maximum levels of safety both for users and the infrastructure includieng, in some parts of the tunnel, fixed fire fighting system based on water mist. Whithin this framework a large-scale programme of fire tests was planned to study different aspects related to fire safety in the tunnels including the phenomena of the interaction between ventilation and extinguishing system. In addition, these large scale fire tests allowed fire brigades of the city of Madrid an opportunity to define operational procedures for specific fire fighting in tunnels and evaluate the possibilities of fixed fire fighting systems. The tests were carried out in the Center of Experimentation "San pedro of Anes" which includes a 600 m tunnel with a removable false ceiling for reproducing different ceiling heights and ventilation conditions (transverse and longitudinal ones). Interesting conclusions on the interaction of ventilation and water mist systems were obtained but also on other aspects including performance of water mist system in terms of reduction of gas temperatures or visibility conditions. This paper presents a description of the test's programme carried out and some previous results obtained.

A Spatial Econometrics Analysis for Road Accidents in Lisbon

This paper presents a spatial econometrics analysis for the number of road accidents with victims in the smallest administrative divisions of Lisbon, considering as a baseline a log-Poisson model for environmental factors. Spatial correlation on data is investigated for data alone and for the residuals of the baseline model without and with spatial-autocorrelated and spatial-lagged terms. In all the cases no spatial autocorrelation was detected.

Aptitude au volant: quelle conduite [Aptitude to drive: what road to take?].

Tout médecin de premier recours devrait pouvoir se prononcer sur l'aptitude à la conduite automobile de son patient. La problématique du conducteur âgé, dépendant soit de l'alcool ou de drogues, sous traitement de médicaments psychotropes, ou encore diabétique, est abordée à la lumière des dispositions légales et des récentes recommandations. Cet article aborde également les aspects relatifs aux problèmes neurologiques, cardiologiques et orthopédiques. Any primary care doctor should be able to decide on the fitness to drive of a given patient. The issue of an older driver, patients addicted to alcohol or drugs, under current psychotropic drug treatment, or diabetic, is discussed in the light of legal provisions and current recommendations. This article also discusses aspects associated with neurological, cardiac and orthopedic issues.

Use of Railroad Flat Cars for Low-Volume Road Bridges, August 1999

In an attempt to solve the bridge problem faced by many county engineers, this investigation focused on a low cost bridge alternative that consists of using railroad flatcars (RRFC) as the bridge superstructure. The intent of this study was to determine whether these types of bridges are structurally adequate and potentially feasible for use on low volume roads. A questionnaire was sent to the Bridge Committee members of the American Association of State Highway and Transportation Officials (AASHTO) to determine their use of RRFC bridges and to assess the pros and cons of these bridges based on others’ experiences. It was found that these types of bridges are widely used in many states with large rural populations and they are reported to be a viable bridge alternative due to their low cost, quick and easy installation, and low maintenance. A main focus of this investigation was to study an existing RRFC bridge that is located in Tama County, IA. This bridge was analyzed using computer modeling and field load testing. The dimensions of the major structural members of the flatcars in this bridge were measured and their properties calculated and used in an analytical grillage model. The analytical results were compared with those obtained in the field tests, which involved instrumenting the bridge and loading it with a fully loaded rear tandem-axle truck. Both sets of data (experimental and theoretical) show that the Tama County Bridge (TCB) experienced very low strains and deflections when loaded and the RRFCs appeared to be structurally adequate to serve as a bridge superstructure. A calculated load rating of the TCB agrees with this conclusion. Because many different types of flatcars exist, other flatcars were modeled and analyzed. It was very difficult to obtain the structural plans of RRFCs; thus, only two additional flatcars were analyzed. The results of these analyses also yielded very low strains and displacements. Taking into account the experiences of other states, the inspection of several RRFC bridges in Oklahoma, the field test and computer analysis of the TCB, and the computer analysis of two additional flatcars, RRFC bridges appear to provide a safe and feasible bridge alternative for low volume roads.

Assessment of driving capability through the use of clinical and psychomotor tests in relation to blood cannabinoids levels following oral administration of 20 mg dronabinol or of a cannabis decoction made with 20 or 60 mg Delta9-THC.

Delta(9)-Tetrahydrocannabinol (THC) is frequently found in the blood of drivers suspected of driving under the influence of cannabis or involved in traffic crashes. The present study used a double-blind crossover design to compare the effects of medium (16.5 mg THC) and high doses (45.7 mg THC) of hemp milk decoctions or of a medium dose of dronabinol (20 mg synthetic THC, Marinol on several skills required for safe driving. Forensic interpretation of cannabinoids blood concentrations were attempted using the models proposed by Daldrup (cannabis influencing factor or CIF) and Huestis and coworkers. First, the time concentration-profiles of THC, 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) (active metabolite of THC), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in whole blood were determined by gas chromatography-mass spectrometry-negative ion chemical ionization. Compared to smoking studies, relatively low concentrations were measured in blood. The highest mean THC concentration (8.4 ng/mL) was achieved 1 h after ingestion of the strongest decoction. Mean maximum 11-OH-THC level (12.3 ng/mL) slightly exceeded that of THC. THCCOOH reached its highest mean concentration (66.2 ng/mL) 2.5-5.5 h after intake. Individual blood levels showed considerable intersubject variability. The willingness to drive was influenced by the importance of the requested task. Under significant cannabinoids influence, the participants refused to drive when they were asked whether they would agree to accomplish several unimportant tasks, (e.g., driving a friend to a party). Most of the participants reported a significant feeling of intoxication and did not appreciate the effects, notably those felt after drinking the strongest decoction. Road sign and tracking testing revealed obvious and statistically significant differences between placebo and treatments. A marked impairment was detected after ingestion of the strongest decoction. A CIF value, which relies on the molar ratio of main active to inactive cannabinoids, greater than 10 was found to correlate with a strong feeling of intoxication. It also matched with a significant decrease in the willingness to drive, and it matched also with a significant impairment in tracking performances. The mathematic model II proposed by Huestis et al. (1992) provided at best a rough estimate of the time of oral administration with 27% of actual values being out of range of the 95% confidence interval. The sum of THC and 11-OH-THC blood concentrations provided a better estimate of impairment than THC alone. This controlled clinical study points out the negative influence on fitness to drive after medium or high dose oral THC or dronabinol.

Correlation Studies BPR Type Roughometer vs. PCE Type Road Meter, MLR-68-2, 1968

The BPR type Roughometer has been used by the Iowa State Highway Commission since 1955 for the evaluation of the relative roughness of the various Iowa road surfaces. Since the commencement of this program, standardized information about the roughness of the various Iowa roads with respect to their type, construction, location and usage has been obtained. The Roughometer has also served to improve the economics and quality of road construction by making the roughness results of various practices available to all who are interested. In 1965, the Portland Cement Association developed a device known as the PCA Road Meter for measuring road roughness. Mounted in a regular passenger car, the Road Meter is a simple electromechanical device of durable construction which can perform consistently with extremely low maintenance. In 1967, the Iowa State Highway Commission's Laboratory constructed a P.C.A. type Road Meter in order to provide an efficient and reliable method for measuring the Present Serviceability Index for the state's highways. Another possibility was that after considerable testing the Road Meter might eventually replace the Roughometer. Some advantages of the Road Meter over the Roughometer are: (1) Road Meter tests are made by the automobile driver and one assistant without the need of traffic protection. The Roughometer has a crew of four men; two operating the roughometer and two driving safety vehicles. (2) The Road Meter is able to do more miles of testing because of its faster testing speed and the fa.ct that it is the only vehicle involved in the testing. (3) Because of the faster testing speed, the Road Meter gives a better indication of how the road actually rides to the average highway traveler. (4) The cost of operating a Road Meter is less than that of a Roughometer because of the fewer number of vehicles and men needed in testing.

Skid Resistance of the Secondary Road System in Iowa, MLR-77-1, 1977

The Iowa Department of Transportation has been conducting skid resistance tests on the paved secondary system on a routine basis since 1973. This report summarizes the data obtained through 1976 on 10,101 miles in 95 of the 99 counties in Iowa. A summary of the skid resistance on the secondary system is presented by pavement type and age. The data indicates that the overall skid resistance on this road system is excellent. Higher traffic roads (over 1000 vehicles per day) have a lower skid resistance than the average of the secondary roads for the same age and pavement type. The use of non-polishing aggregates in asphaltic concrete paving surface courses and transverse grooving of portland cement concrete paving on high traffic roads is recommended. The routine resurvey of skid resistance on the secondary road system on a 5-year interval is probably not economically justified and could be extended to a 10-year interval.

Demonstration Project using Railroad Flatcars for Low-Volume Road Bridges, TR-444, 2003

The use of Railroad Flatcars (RRFCs) as the superstructure on low-volume county bridges has been investigated in a research project conducted by the Bridge Engineering Center at Iowa State University. These bridges enable county engineers to replace old, inadequate county bridge superstructures for less than half the cost and in a shorter construction time than required for a conventional bridge. To illustrate their constructability, adequacy, and economy, two RRFC demonstration bridges were designed, constructed, and tested: one in Buchanan County and the other in Winnebago County. The Buchanan County Bridge was constructed as a single span with 56-ft-long flatcars supported at their ends by new, concrete abutments. The use of concrete in the substructure allowed for an integral abutment at one end of the bridge with an expansion joint at the other end. Reinforced concrete beams (serving as longitudinal connections between the three adjacent flatcars) were installed to distribute live loads among the RRFCs. Guardrails and an asphalt milling driving surface completed the bridge. The Winnebago County Bridge was constructed using 89-ft-long flatcars. Preliminary calculations determined that they were not adequate to span 89 ft as a simple span. Therefore, the flatcars were supported by new, steel-capped piers and abutments at the RRFCs' bolsters and ends, resulting in a 66-ft main span and two 10-ft end spans. Due to the RRFC geometry, the longitudinal connections between adjacent RRFCs were inadequate to support significant loads; therefore, transverse, recycled timber planks were utilized to effectively distribute live loads to all three RRFCs. A gravel driving surface was placed on top of the timber planks, and a guardrail system was installed to complete the bridge. Bridge behavior predicted by grillage models for each bridge was validated by strain and deflection data from field tests; it was found that the engineered RRFC bridges have live load stresses significantly below the AASHTO Bridge Design Specification limits. To assist in future RRFC bridge projects, RRFC selection criteria were established for visual inspection and selection of structurally adequate RRFCs. In addition, design recommendations have been developed to simplify live load distribution calculations for the design of the bridges. Based on the results of this research, it has been determined that through proper RRFC selection, construction, and engineering, RRFC bridges are a viable, economic replacement system for low-volume road bridges.

A Continuous Span Aluminum Girder Concrete Deck Bridge - Part 2 of 2: Fatigue Tests of Aluminum Girders, Final Report, 1997

In 1957, the Iowa State Highway Commission, with financial assistance from the aluminum industry, constructed a 220-ft (67-m) long, four-span continuous, aluminum girder bridge to carry traffic on Clive Road (86th Street) over Interstate 80 near Des Moines, Iowa. The bridge had four, welded I-shape girders that were fabricated in pairs with welded diaphragms between an exterior and an interior girder. The interior diaphragms between the girder pairs were bolted to girder brackets. A composite, reinforced concrete deck served as the roadway surface. The bridge, which had performed successfully for about 35 years of service, was removed in the fall of 1993 to make way for an interchange at the same location. Prior to the bridge demolition, load tests were conducted to monitor girder and diaphragm bending strains and deflections in the northern end span. Fatigue testing of the aluminum girders that were removed from the end spans were conducted by applying constant-amplitude, cyclic loads. These tests established the fatigue strength of an existing, welded, flange-splice detail and added, welded, flange-cover plates and horizontal web plate attachment details. This part, Part 2, of the final report focuses on the fatigue tests of the aluminum girder sections that were removed from the bridge and on the analysis of the experimental data to establish the fatigue strength of full-size specimens. Seventeen fatigue fractures that were classified as Category E weld details developed in the seven girder test specimens. Linear regression analyses of the fatigue test results established both nominal and experimental stress-range versus load cycle relationships (SN curves) for the fatigue strength of fillet-welded connections. The nominal strength SN curve obtained by this research essentially matched the SN curve for Category E aluminum weldments given in the AASHTO LRFD specifications. All of the Category E fatigue fractures that developed in the girder test specimens satisfied the allowable SN relationship specified by the fatigue provisions of the Aluminum Association. The lower-bound strength line that was set at two standard deviations below the least squares regression line through the fatigue fracture data points related well with the Aluminum Association SN curve. The results from the experimental tests of this research have provided additional information regarding behavioral characteristics of full-size, aluminum members and have confirmed that aluminum has the strength properties needed for highway bridge girders.

A Road Following Approach Using Artificial Neural Networks Combinations

Navigation is a broad topic that has been receiving considerable attention from the mobile robotic community over the years. In order to execute autonomous driving in outdoor urban environments it is necessary to identify parts of the terrain that can be traversed and parts that should be avoided. This paper describes an analyses of terrain identification based on different visual information using a MLP artificial neural network and combining responses of many classifiers. Experimental tests using a vehicle and a video camera have been conducted in real scenarios to evaluate the proposed approach.