Vehicle Design Changes Research Articles

Development of the Construction of City Buses in Terms of Reducing the Curb Weight of the Vehicle

Modern city buses are made of various construction materials and the share of material groups has changed over the decades. By replacing heavy materials for structural elements or bus components with their lighter counterparts, the kerb weight of the bus can be reduced by up to several hundred kilograms. This article presents the issues of the development of city bus design in terms of passenger space comfort and bus structure in the context of reducing the vehicle's own weight since the 1970s. The main changes in vehicle design allowing for reducing the weight of structural elements of bodies and chassis as well as the main assemblies in city buses are presented as well as research on body types in terms of aerodynamics, safety and travel comfort. It has been shown that reducing the weight of the bus does not negatively affect its load capacity and the new bus designs are equipped with safety and comfort systems, including ABS (Anti-lock Braking System), ASR (Automatic Stability Regulation), ESP (Electronic Stability Program) and air conditioning in the passenger space. Thanks to modern light construction materials, we gain the opportunity to improve safety and comfort without losing the transport capabilities developed as a result of the development of city buses over the years.

The effect of sustainable mobility transition policies on cumulative urban transport emissions and energy demand

The growing urban transport sector presents towns and cities with an escalating challenge in the reduction of their greenhouse gas emissions. Here we assess the effectiveness of several widely considered policy options (electrification, light-weighting, retrofitting, scrapping, regulated manufacturing standards and modal shift) in achieving the transition to sustainable urban mobility in terms of their emissions and energy impact until 2050. Our analysis investigates the severity of actions needed to comply with Paris compliant regional sub-sectoral carbon budgets. We introduce the Urban Transport Policy Model (UTPM) for passenger car fleets and use London as an urban case study to show that current policies are insufficient to meet climate targets. We conclude that, as well as implementation of emission-reducing changes in vehicle design, a rapid and large-scale reduction in car use is necessary to meet stringent carbon budgets and avoid high energy demand. Yet, without increased consensus in sub-national and sectoral carbon budgets, the scale of reduction necessary stays uncertain. Nevertheless, it is certain we need to act urgently and intensively across all policy mechanisms available as well as developing new policy options.

Fire Hazard Analysis of Modern Vehicles in Parking Facilities

Vehicle fires in parking structures developing into large conflagrations are rare but can result in severe economic losses. It is important to understand the hazard posed by modern vehicle fires to determine whether current fire codes for parking garages are mandating adequate fire protection requirements. There has been an increase in the fire hazard from changes in vehicle design and increased use of plastics and other combustible materials in vehicle construction, along with denser parking of vehicles in parking structures. This manifests as faster flame spread within the vehicle, easier ignition and more rapid fire spread to neighboring vehicles. Based on the findings, test data from vehicles older than 2000–2005 model years should not be used as basis for development of codes and regulations. Open parking structures emerge as the main area of concern regarding fires in modern vehicles. The lack of any requirements for active protection systems in the fire codes, and trends in vehicle and garage design suggest that large, devastating fires in these structures could become increasingly common. The spread of fire between vehicles, especially from the initial to the second and third vehicles, is critical in determining the extent of the fire and the ability of the fire department to successfully control and extinguish. Future research should be conducted into earlier detection, sprinkler protection, and fire spread between vehicles to address the hazard.

Pedestrian injuries from cars and SUVs: Updated crash outcomes from the vulnerable road user injury prevention alliance (VIPA)

Objective The current short communication was written to update research on real-world pedestrian crashes. In particular, our analysis offers a preliminary update on SUV-pedestrian crash outcomes and how they differ from car-pedestrian crash outcomes. Detailed injury data were linked to vehicle features to offer a better understanding of pedestrian injury etiology. Methods We analyzed 82 single-vehicle crashes from the VIPA pedestrian crash database, focusing on crashes involving an SUV or car. Each crash from this database includes an in-depth analysis of police reports, pedestrian medical records, crash reconstructions, and injury attribution by a panel of experts. Results SUVs remain disproportionately likely to injure and kill pedestrians compared with cars, but these differences emerged primarily at crashes of intermediate speed. Crashes at low speeds and high speeds tend to produce similar injury outcomes independent of striking vehicle type (mild and fatal, respectively). The data suggest that the elevated danger to pedestrians from SUVs in these crashes may be largely related to injuries caused by impacts with the vehicles’ leading edge: the bumper, grille, and headlights. Conclusions Although the current analysis was based on a non-nationally representative dataset, the elevated pedestrian injury risk originating from SUVs’ leading edge is consistent with past research on the subject. That is, despite the changes in vehicle design and fleet composition over the past two decades, SUVs may remain disproportionately likely to injure pedestrians compared with cars.

Robust Flight Control Using Nonsmooth Optimization for a Tandem Ducted Fan Vehicle

AbstractThis work addresses the aerodynamic modeling and near‐hover‐flight control design for an unconventional aerial robot of the tandem ducted fan configuration, which is intended to be prototypical of a flight service vehicle. The main model elements of this novel unmanned vehicle, which exhibit highly nonlinear and unstable open‐loop modes, are presented. A frequency‐domain controllability analysis concerning the plant's behavior around the hovering flight condition is then adopted to determine the expected control performance, which is of important practical significance to controllability improvement through vehicle design changes. A robust controller that stabilizes the unmanned vehicle under wind disturbances is designed using a newly developed nonsmooth optimization algorithm, which rigorously and efficiently tunes the arbitrarily predefined structured controller against multiple control requirements. A successive two‐loop architecture is employed in the designed controller. In this architecture, the inner loop provides stability augmentation and decoupling, and the outer loop guarantees the desired velocity tracking performance. Simulation results under stochastic wind gusts are presented to verify the performance of the proposed controllers. Preliminary flight tests are also carried out to demonstrate the performance of the system.

Seatbelt Use and Related Factors Among Drivers Involved in Road Crashes in Southeast Iran

Background: Seatbelts are a relatively low-cost safety device that provides easy basic protection for occupants of 4-wheeled vehicles. Objectives: This study investigates frequency of seatbelt use and its related factors among drivers involved in a vehicle crash. Materials and Methods: In this cross-sectional study, all crash profiles recorded in a province from March 2010 to March 2011 were reviewed. Necessary information was extracted from crash reports in which at least one 4-wheeled vehicle was involved. Data were analyzed using binary and multinomial logistic regression. Results: Of a total of 1427 motor vehicle crashes, a seatbelt was used by 58.2% of drivers. In the univariate analysis, the following were significantly associated with seatbelt use: driver age, education, and occupation along with front seat passenger's sex and seatbelt use, type and make of vehicle, speed, road surface condition, and type of road. In the multivariate model, the following remained significant: driver education, seatbelt use by front seat passenger, and type of road. Furthermore, a restraining seatbelt protected drivers from severe injury and death. Unbelted drivers were 7 and 17.4 times more likely to experience injury and death respectively than belted drivers. Conclusions: The seatbelt wearing rate among the study participants was much lower than the 90% rate reported among Iranian drivers in 2010. Mandating seatbelt use, as in most countries, will be more effective if a combination of factors such as changes in vehicle design, road safety, and driver and passenger behavior are taken into account.

The Effects of Vehicle Redesign on the Risk of Driver Death

Objectives: This study updates a 2006 report that estimated the historical effects of vehicle design changes on driver fatality rates in the United States, separate from the effects of environmental and driver behavior changes during the same period. In addition to extending the period covered by 8 years, this study estimated the effect of design changes by model year and vehicle type.Methods: Driver death rates for consecutive model years of vehicle models without design changes were used to estimate the vehicle aging effect and the death rates that would have been expected if the entire fleet had remained unchanged from the 1985 calendar year. These calendar year estimates are taken to be the combined effect of road environment and motorist behavioral changes, with the difference between them and the actual calendar year driver fatality rates reflecting the effect of changes in vehicle design and distribution of vehicle types. The effects of vehicle design changes by model year were estimated for cars, SUVs, and pickups by computing driver death rates for model years 1984–2009 during each of their first 3 full calendar years of exposure and comparing with the expected rates if there had been no design changes.Results: As reported in the 2006 study, had there been no changes in the vehicle fleet, driver death risk would have declined during calendar years 1985–1993 and then slowly increased from 1993 to 2004. The updated results indicate that the gradual increase would have continued through 2006, after which driver fatality rates again would have declined through 2012. Overall, it is estimated that there were 7,700 fewer driver deaths in 2012 than there would have been had vehicle designs not changed. Cars were the first vehicle type whose design safety generally exceeded that of the 1984 model year (starting in model year 1996), followed by SUVs (1998 models) and pickups (2002 models). By the 2009 model year, car driver fatality risk had declined 51% from its high in 1994, pickup driver fatality risk had declined 61% from its high in 1988, and SUV risk had declined 79% from its high in 1988. The risk of driver death in 2009 model passenger vehicles was 8% lower than that in 2008 models and about half that in 1984 models.Conclusions: Changes in vehicles, whether from government regulations and consumer testing that led to advanced safety designs or from other factors such as consumer demand for different sizes and types of vehicles, have been key contributors to the decline in U.S. motor vehicle occupant crash death rates since the mid-1990s. Since the early 1990s, environmental and behavioral risk factors have not shown similar improvement, until the recession of 2007, even though there are many empirically proven countermeasures that have been inadequately applied.

EXHAUST EMISSION MEASUREMENTS IN THE DEVELOPMENT OF SUSTAINABLE ROAD TRANSPORT

Economic development of nations leads to a higher living comfort of the society. Rich societies want to move safely and independently and demand immediate availability of purchased goods or – in the case of Internet shopping – delivery in the shortest possible time. Such an approach facilitates a continuous growth in the number of road vehicles. At the current level of technology advancement, an increasing number of vehicles results in a growth of the consumption of fossil fuels, which entails increased exhaust emissions and that, in turn, has a negative impact on the health of the living organisms. Another negative consequence of an increased number of vehicles (increased road congestion) is the emission of noise. This problem is particularly significant in large agglomerations where people are surrounded by moving vehicles. This paper presents the extent of influence of the automotive industry on the natural environment and the extent of changes in vehicle design and organization of road infrastructure that were instituted to reduce the transport’s environmental burden. The further part of the paper presents a definition of the development of sustainable transport, its advantages and hurdles that we may encounter when modernizing a transport system. Subsequently in the paper, the measurements under actual vehicle operating conditions were described together with the possibilities of analysis of the research results and the advantages resulting from such an approach during the assessment of the impact of the automotive industry on the natural environment.

ENGINE TESTING OF RME ADDITIVES

Reducing the emission of pollutants emitted motor vehicles, and now also in greenhouse gas emissions, is a result of European Union policy. Vehicle design changes are just one way of reducing emissions of harmful substances and greenhouse gases. The second way is to change the type of fuel, by which the vehicle's engine is powered, that is the substitution of conventional fossil fuels derived crude oil, such as gasoline or diesel fuel by so-called renewable fuels, for which the CO2 emissions are measured not only in the engine exhaust system, but also by analysis from the source to the wheel WTW (Well-to-wheel) - is much smaller. As part of this task the Directive 2009/28/EC introduced for all Member States to the use of renewable energy, biofuels, alternative fuels to a certain extent share of the energy and conventional fuel by 2020. This paper presents the results of measurements of emissions on the dynamometer with a diesel engine powered by six kinds of mixtures of diesel oil and rapeseed oil methyl ester (RME) – with esters containing 0 (clean diesel), 20, 40, 60, 80 and 100 (pure rapeseed oil methyl esters)% in the fuel. We analysed the reasons for the impact of changes in fuel composition on selected limited exhaust components. We found, that the addition of esters of rapeseed oil to the diesel fuel can be a reason of reducing the emissions of CO, CO2, and THC in the exhaust gases of tested engine and increased emissions of NOx and PM.

Estimation of Secondary Mass Changes in Vehicle Design

Estimation of Secondary Mass Changes in Vehicle Design

A Systematic Review of Driver Ingress and Egress Using Passenger Vehicles: Considerations for Designers

Identifying ingress and egress strategies is an important area of research in the automotive sector. Determining ingress and egress strategies can lead to safer vehicle design that reduce fall risk and improve comfort. In this systematic review, we examined studies related to ingress and egress in passenger vehicles after searching for various databases. We found 9 primary articles (of 608), all published in English. The results of the present research synthesis show that participants reported challenges with doorway height, sill height during ingress and egress, as well as will width during egress. There are also various ingress and egress strategies employed by drivers. However, ingress and egress strategies did not differ significantly by sample characteristics (i.e., age, height) or vehicle type. Roof height was not a factor of ingress and egress strategies although a large sill width may increase the risk of adverse events during egress. Future studies need to incorporate larger and more heterogeneous samples (i.e., healthy versus non-healthy, younger versus older adults) and relate participant characteristics (i.e., age, gender, height, weight) and the use of hands (along with force measurements) with ingress and egress strategies. Additionally, changes in vehicle design should be modelled with comfort ratings using metrics and loss functions to determine the optimal point between comfort and safety. This is the first review of the ingress and egress literature to summarize important findings and provide directions for future research.

Deaths among Drivers and Right-Front Passengers in Frontal Collisions: Redesigned Air Bags Relative to First-Generation Air Bags

Objective. After automakers were allowed the option of using sled tests for unbelted male dummies to certify the frontal crash performance of vehicles, most frontal air bags were depowered, starting in model year 1998, to reduce deaths and serious injuries arising from air bag deployments. Concern has been expressed that depowering air bags could compromise the protection of adult occupants. This study aimed to determine the effects of changes in air bag designs on risk of death among front-seat occupants. Methods. Deaths among drivers and right-front passengers per involvement in frontal police-reported crashes during calendar years 1998–2004 were compared among vehicles with sled-certified air bags (model years 1998–2004) and first-generation air bags (model years 1994–97). Frontal crash deaths were identified from the Fatality Analysis Reporting System. National estimates of police-reported crashes were derived from the National Automotive Sampling System/General Estimates System. Sled certification status for model years 1998–2004 was ascertained from published federal data and a survey of automobile manufacturers. Passenger cars, pickup trucks, sport utility vehicles, and minivans were studied. Stratified analyses were done to compute risk ratios (RR) and 95% confidence intervals (95% CI) for driver and right-front passenger deaths by air bag generation and crash, vehicle, and driver characteristics. Results. In frontal crashes, overall RRs were 0.89 for driver deaths (95% CI = 0.74–1.08) and 0.89 for right-front passenger deaths (95% CI = 0.74–1.07) in sled-certified vehicles compared with first-generation air bag–equipped vehicles. Child right-front passengers (ages 0–4, 5–9) in vehicles with sled-certified air bags had statistically significant reductions in risk of dying in frontal collisions, including a 65% reduced risk among ages 0–4 (RR = 0.35; 95% CI = 0.21–0.60). No differences in effects of sled-certified air bags were observed between drivers ages 15–59 and 60–74 in sled-certified vehicles, both of whom had RRs slightly below 0.90 (non-significant). Among occupants killed in sled-certified vehicles, police-reported belt use was somewhat higher than in first-generation vehicles. Conclusions. No differences in risk of frontal crash deaths were observed between adult occupants with sled-certified and first-generation air bags. Consistent with reports of decreases in air bag–related deaths, this study observed significant reductions in frontal deaths among child passengers seated in the right-front position in sled-certified vehicles. Higher restraint use rates among children in sled-certified vehicles and other vehicle design changes might have contributed partially to these reductions.

Trends Over Time in the Risk of Driver Death: What If Vehicle Designs Had Not Improved?

Objectives. Passenger vehicle driver death rates per million vehicle registrations declined steadily during calendar years 1985–2004. The present study sought to separate the effect of vehicle design changes from this trend. Methods. Restricting the trend to a fixed set of model years removed the vehicle design effects, but there were still effects due to vehicle aging. Risk of driver death was found to increase each year vehicles aged, probably due to changes in vehicle use patterns. Results. After separating out the vehicle design effects and making adjustments for the vehicle age effects, a different picture emerged of trends in death rates over time. Absent the vehicle design changes, the historical decline in driver fatality risk would have ended in 1993, with risk climbing ever since. This underlying trend has been obscured by changes in the vehicle fleet. Conclusions. The push for vehicle improvements has been worthwhile and can be credited with saving thousands of lives. However, the analysis shows that the gains in occupant protection from vehicle design improvements have been offset partially by an increasingly risky environment in recent years. Therefore, more attention needs to be paid to programs targeting improvement in roadway design and driver behavior.

Product service systems in the automobile industry: contribution to system innovation?

This article investigates the actual and potential contribution that product service systems (PSSs) can make in moving beyond incremental technological improvements towards a focus on behavioural changes and system innovation in the automobile industry. It begins by discussing the means by which existing and planned PSS initiatives can be evaluated in terms of their contribution towards innovation at the system level in the automotive industry. Building on and expanding earlier work, it is suggested that they should be assessed against an expanded set of five key evaluative criteria including: evidence of ‘higher-order’ learning amongst stakeholders; changes in infrastructure and institutional practice; changes in vehicle design, manufacture and end-of-life management; changes in vehicle ownership structure; and changes in modes of producer–user interactions. Following this discussion, the article provides a structured overview of some current and planned PSS initiatives at the empirical level in the automotive industry. The identified initiatives are then assessed against the key evaluative criteria in an effort to reveal their actual or potential contribution to meeting the sustainability challenges of the automotive industry. Based on this exercise, it is argued that since most current initiatives do not unify these key elements of a PSS in a single coherent system they do not constitute ‘complete’ versions of PSS, and therefore, fail to deliver the full range of envisaged benefits in contributing towards system innovation. The article concludes by outlining some key areas for future research into potential strategies to address such challenges.

Pedestrian crashes: higher injury severity and mortality rate for light truck vehicles compared with passenger vehicles

Introduction: During the last two decades changes in vehicle design and increase in the number of the light truck vehicles (LTVs) and vans have led to changes in pedestrian injury...

Future vehicles: an introduction

Many researchers doubt that the familiar car can continue on the course developed over the past half-century or more. Environmental and resource problems from the manufacture, operation, and disposal of cars will require major changes in vehicle design and manufacturing methods, and in the materials and fuels used. Growing world car ownership is increasing both road congestion and traffic fatalities, and both factors could also influence future car design. At the same time, advances in Information Technology appear to offer new approaches to vehicle design, congestion, and safety. This paper briefly examines the various factors that will shape future vehicle design, fuels, infrastructure, and industry. We find that forecasting what will happen in any of these areas is becoming an increasingly difficult task, although some trends have appeared which provide some degree of insight.

Wavelength-Related Ride Equation

The existing equation used by the Texas Department of Transportation (TxDOT) to evaluate ride quality from measured profiles is based on measurements obtained from a rating session conducted in the late 1960s. Since its original development more than 30 years ago, a number of changes have required a reevaluation of the current equation. These include changes in vehicle design, such as improvements in vehicle suspension and handling characteristics, and the switch from the predominantly large automobiles used in the late 1960s to the smaller and more fuel-efficient midsized and compact cars of today. Additionally, TxDOT has changed the section interval used for reporting ride or present serviceability index from 0.2 to 0.1 mi. A new ride equation based on a specific set of profile wavelengths is described. In addition, possible uses of the equation for construction control and bump detection are discussed.

Medical treatment and traffic fatality reductions in industrialized countries

Reductions in traffic-related fatalities in developed industrialized countries have been substantial in the last 30 years. Most analyses have attributed this reduction to changes in vehicle design, better road design, increased seat-belt use, and reductions in driving under the influence of alcohol. This paper analyses the impact of improvements in medical treatment and technology. Data from the International Road and Traffic Accident Database (IRTAD), which includes all developed countries, was used in combination with Organization for Economic Cooperation and Development (OECD) Health Care data. Using proxy measures to account for improvements in medical treatment and technology it is found that these proxy variables are significant and capture much of the residual time trend in the data when they are omitted. Changes in age cohorts, such as fewer young people, also have contributed to a reduction in fatalities. These results suggest that medical technology improvements are associated with reductions in traffic-related fatalities over time.

Exploring the Paradigm Shifts Needed To Reconcile Transportation and Sustainability Objectives

A sustainable economy is sensitive to economic, social, and environmental constraints. Sustainability requires more efficient, equitable, and environmentally sensitive transport. This cannot be achieved simply by changes in vehicle design or improved traffic management. It requires changes in the way we think about transportation, and how we identify and evaluate solutions to transport problems—“paradigm shifts.” This paper discusses these changes and their implications for transportation decision making. Sustainability requires rethinking how we measure transportation. Transport planners often treat vehicle movement as an end in itself. Sustainable transportation planning focuses on access, which can often be improved with strategies that reduce the need to travel altogether, such as land use management and improved communications. Sustainability requires comprehensive decision making that takes into account indirect and interrelated effects. Sustainable transport planning begins with a community’s strategic plan, which individual transportation decisions must support. It requires policies that reward individuals, agencies, and communities for achieving sustainability objectives. There are many specific transportation strategies that can help support sustainability, including improved travel choices, more efficient pricing, and more efficient land use. Individually such strategies may have modest impacts, but implemented together they can provide substantial benefits. At least onethird of current motor vehicle use could be reduced by eliminating market distortions that encourage inefficient travel.

Child Pedestrian Injuries in the United States

Each year in the United States, more than 50,000 children are injured as pedestrians, of whom approximately 1800 die, 18,000 are admitted to the hospital, and 5000 have significant long-term sequelae. Prevention must rest on a multifaceted approach at the local, state, and national level and should include pedestrian skills training programs, parent education, legislation, environmental modifications, and vehicle design changes.