Car Use Research Articles

City-wide cycling network extension and bicycle ridership in São Paulo: A causal analysis

Over the past 15 years, São Paulo, a megacity in Southeastern Brazil, has tackled its enduring mobility challenges by constructing over 500 km of bike routes and supporting various cycling initiatives, including recreational cycling programs, mobility strategies and bikeshare. Despite the generally positive impacts of these initiatives, the absence of robust causal evidence on their benefits can pose serious challenges for future investments in light of the existing social dynamic favoring the use of automobiles. Driven by the need to reduce motorized transport in Brazilian cities, we investigate the causal effects of bicycle routes on ridership between 2007 and 2017, focusing on travellers highly exposed to bike routes developed between 2008 and 2015. Using Difference-in-Differences models alongside Household Travel Surveys conducted before and after the interventions, we observed a modest but positive increase in cycling mode choice probability, ranging from 0.60 % to 1.37 %, among the highly exposed treatment groups. Our findings provide policymakers with valuable insights to support future cycling infrastructure planning and investment, demonstrating their potential net benefits even in car-dependent urban areas. By integrating these results into existing economic appraisal tools, policymakers can further assess additional benefits related to physical activity, health, and emissions reduction.

Exploring potential car trips for long-distance school escorting using smart card data and a household travel survey

Encouraging students to commute by the metro can effectively reduce household car use caused by long-distance commuting to school. This article focuses on the frequency of metro use by groups of students commuting to school based on the assumption that students who use the metro may occasionally be driven to school by their parents. For the 1st time, we propose a school metro commuter identification process that considers the potential behaviour of escorted students, and we study the potential car trips for long-distance school escorting in Nanjing (China) using Smart Card Data (SCD) and a household travel survey from Nanjing. 3 clusters of students who use the metro for commutes to school are identified by frequency of use for possible escorting behaviour based on the commuting day. As possible factors influencing the 3 frequency groups, usage pattern of the metro, entry time, travel duration and the school–housing relationship are extracted from SCD. Furthermore, a multinomial logistic regression model is used to examine the significant factors that influence the grouping of students. The results show that students who use the metro occasionally for a long commuting distance to school are more likely to be escorted to and from school by their parents, especially to school. The later the entry time is to the metro, the more likely that students are to be escorted to school. Additionally, a long school–housing travel duration/distance significantly contributes to parents’ car trips for commuting. The results of this article are valuable for transport policy to reduce car use for long-distance school trips.

“Everyone Wants to Drive There”: Challenges to Transport Sustainability in Rural Tourism Destinations

ABSTRACTUnderstanding transport challenges is inevitable for transitioning to a low‐carbon rural tourism future. Using social representation theory, this study examines how tourism and transport practitioners perceive transport challenges in rural destinations and how they overcome these problems. The multi‐method qualitative approach adopted involves semi‐structured interviews with practitioners, participant observation, and document analysis in the Swedish destinations of Åre and Sälen. Findings reveal social representations of transport challenges at both destinations, namely, “a car‐dependent society”, a “non‐desirable transport future” and “wicked transport problems”. Practitioners in these places address these challenges in several ways. Surprisingly, one solution is to promote flying to the destinations. This particular solution, not to mention the destinations' overreliance on private automobile use illustrates that they have not yet begun transitioning to a low carbon transport future. This situation highlights the urgency to encourage sustainable mobility development to and within these destinations.

Interactive Effects of Built Environment and Parking Policy on Car Use: Examining Differences Between Work and Non-Work Trips

Considerable interest has been shown in decreasing car use through planning and policy-making efforts. However, little is known about the interactive effects of built environment (BE) and parking policy on car use, and it is unclear whether and how these effects differ across trip purposes. We conducted a web-based survey in Beijing and collected data from 1036 respondents, including 517 male and 519 female respondents. This study estimates the interactive effects of BE and parking policy on car use for home-based work and non-work trips by employing multilevel logit models. The results show that BE variables at trip origins and destinations are important for shaping car use for both home-based work and non-work trips. Specifically, land use mixture (Coeff. = −0.121), bus stop density (Coeff. = −0.006), and population density (Coeff. = −0.009) at residential locations are negative factors affecting car use for work trips, whereas distance to local center (Coeff. = 0.012) and distance to the city center (Coeff. = 0.019) at residential locations are positive factors. Land use mixture (Coeff. = −0.323), bus stop density (Coeff. = −0.008), road density (Coeff. = −0.002), and population density (Coeff. = −0.007) at residential locations are negative factors of car use for non-work trips. Among BE factors at destinations, land use mixture (Coeff. = −0.319), bus stop density (Coeff. = −0.015), road density (Coeff. = −0.008), distance to the local center (Coeff. = −0.018), and population density (Coeff. = −0.012) are negative factors for car use for work trips, whereas the negative factors for non-work trips are land use mix (Coeff. = −0. 218), bus stop density (Coeff. = −0.038), road density (Coeff. = −0.003), distance to the city center (Coeff. = −0.121), and population density (Coeff. = −0.009). The effects of BE variables can be strengthened or weakened by free parking and parking convenience. Moreover, the results identify significant differences in the effects between work and non-work trips. These findings inform planners and policymakers of how to coordinate the BE and parking policies to decrease car dependence.

Association between school commuting and adolescent mental health: Insights from a longitudinal study amid the pandemic

This study investigates the relationship between transportation modes and adolescent mental health, employing a natural experiment design to longitudinally track Brazilian high-school students amid the COVID-19 pandemic disruptions. We surveyed 213 students in the city of Curitiba during and after the COVID-19 lockdown period using the Depression, Anxiety, and Stress Scale (DASS-21) combined with a socioeconomic questionnaire. To analyze changes in DASS between these two times we used the paired-sample T-test, exploring association with school commuting modes through binomial logistic regression models. The use of public transportation emerges as a significant factor associated with a threefold odds of increasing depression levels among students (OR = 3.08). This likelihood nearly quadrupled (OR = 3.81) when considering students living 5 km or more from school. These findings unveil public transportation and home-school distance as critical factors in the development of depression among adolescents. For example, individuals who commute via individual motorized transportation demonstrate a markedly lower likelihood of experiencing depression, pointing to broader societal and environmental factors such as family income and access to opportunities. Despite appearing contradictory to the commonly understood impacts of car use on mental health, this observation may unveil overlapping layers of spatial inequality and underscore the nuanced dynamics between transportation modes and adolescent mental well-being.

Evaluation of Fuel Consumption and Exhaust Emissions in a Single Cylinder Four-Stroke Diesel Engine Using Biodiesel Derived from Chicken Waste with Additives

Biodiesel is a renewable, locally generated fuel made from vegetable oils, trans fats, or recycled restaurant grease for use in diesel automobiles and other diesel-powered equipment. The physical qualities of biodiesel are comparable to those of petroleum diesel. Biodiesel is used in compression-ignition engines in the same way as petroleum diesel. Biofuel can be made from biomass, but according to the Indian National Policy on Biofuels, biofuel extraction from edible oils is not permitted because it would result in a massive increase in consumer goods prices and perhaps lead to product scarcity. Hence, there is a need to search for alternative biofuel so that it does not affect our nation's national policy. Recently there has been a drastic increase in the consumption of chicken grown in farms. There is a huge problem in disposing of their waste. One major difficulty in waste treatment is poultry manure, often known as slaughter waste. This waste is sometimes dumped on wastelands, roadsides, and the banks of rivers, lakes, and ponds. This creates more sanitary problems for society. According to polls, poultry feces begin to decompose in around three hours. The odor of butcher's waste causes a lot of pollution in the air, as well as an increase in the density of bacteria in the atmosphere. Measures have been taken by the government for the safe disposal of these wastes. One of the major ways of disposal is to recycle this chicken slaughter waste in a useful manner so that it can serve society in a positive way. This could be done by converting this waste into fuel through various processes such as rendering, hydrolysis, extraction, acid esterification, alkaline transesterification, and finally by the extraction process. This produced fuel could be blended with existing diesel in varying concentrations and used in diesel engine-powered vehicles. In this work, the fuel is extracted from the chicken waste and blended with pure diesel and an Al2O3 additive in various proportions. These combinations are then tested on a single-cylinder diesel engine for fuel consumption and emission analysis. The results exhibited an overall better performance when compared to pure diesel.

Planning Public Space Climate Comfortability: A GIS-Based Algorithm for the Compact Cities of the Far North

The issue of forming a comfortable environment in cities with complex climatic conditions has always been an urgent and difficult issue for urban planners. Cities located in the territories of the Far North are characterized by extremely harsh climatic characteristics that affect the planning solutions for the public spaces of the city. Low temperatures and strong winds reduce the time of comfortable stay in the open air, which leads to a decrease in the mobility of the population in the city and stimulates the use of personal cars. The research question is the rational placement of points of interest on the street network to ensure a comfortable travel time between objects. The research methodology of public space planning taking into account the climatic comfortability of Far North cities is proposed in this article. Also, an automated GIS-based algorithm for determining intermediate points on linear objects to increase POIs’ connectivity for the development of the public space of Far North cities under the condition of organizing climatic comfort is proposed. Development of safe and comfortable public space on the basis of network accessibility, taking into account the difficult climatic conditions of these cities, will increase the social activity of the population and tourists, as well as promote economic growth and business development in the city.

Empirical Evaluation of the Replacement of Conventionally Powered Vehicles with Hybrid and Electric Vehicles on the Example of the Poznań Agglomeration

From the collected data of the Central Register of Vehicles, an average of 15,000 vehicles were registered per month in the Greater Poland region in 2020–2022. It should be borne in mind that most of them were conventionally powered cars-spark-ignition or compression-ignition engines, the daily operation of which negatively affects the environment. Institutions responsible for regulating the homologation of passenger vehicles are introducing increasingly stringent emission standards to reduce the harmful effects of vehicles on the environment. In addition, more and more public campaigns are being conducted on the use of cars equipped with alternative propulsion systems, e.g., electric, full-hybrid or increasingly popular hydrogen-powered vehicles. The publication presents forecasts for the replacement of vehicles equipped with spark-ignition and compression-ignition engines with cars equipped with hybrid propulsion systems or electric systems. Tests of vehicles in real operating conditions were carried out in the Poznań agglomeration in an urban area, where the number of vehicles per area is higher than in the case of a nonurban zone. The research objects were both cars equipped with a conventional drivetrain and a hybrid system. The research made it possible to draw up a hybridization index, which was then applied to the number of vehicles registered over the past few years.

An integrated policy approach for sustainable decarbonization pathways of energy system in a city under climate change scenarios

An integrated assessment model has been developed to estimate useful energy demand, followed by an optimization model for planning the energy supply. Four scenarios have been developed. The findings of this study highlight the impact of behavioral, climate change, and socio-economic factors on energy demand and supply. Specifically, these factors can lead to significant variations in demand, such as a more than 3.48-fold difference in cooling demand or a 1.75-fold difference in the transportation demand by cars across various scenarios.The use of a dual-fuel car and electric motorcycle is suggested in all scenarios. Waste processing has been done with a landfill in all scenarios except in the final years of the net-zero emission target scenario, where an incinerator is proposed. The supply model for electricity generation in the early years suggests the combined cycle power plant followed by solar energy at the end. However, in the low-cost electricity scenario, it is always suggested to import electricity. The sensitivity analysis showed that the emission penalty and electricity price are the most important parameters. The results of this study will help policymakers and decision-makers in energy system planning and provide researchers with appropriate information, tools, and methods for future research.

Social Disadvantage and Transportation Insecurity in Clubfoot Clinic.

This study aims to evaluate the association of missing clubfoot clinic visits with transportation barriers and measures of socioeconomic status including the child opportunity index (COI). An 11-question survey was administered to caregivers of patients with clubfoot seen at a single pediatric tertiary hospital between August 2020 and September 2023. A chart review was conducted to obtain zip codes used to determine COI 2.0 scores. The impact of race/ethnicity, income, persons per household, COI, and transportation methods on missing at least one clinic visit was analyzed using descriptive and nonparametric statistics. The transportation survey was completed by a total of 99 caregivers. The median travel time to the clinic was 45 minutes (IQR: 33, range: 1 to 180). Most participants reported use of a personal car (108/128, 83%), and 72% took time off work to attend the appointment. Those with lower COI had longer travel time (P=0.02) and were less likely to use personal cars (P=0.05). Missed clubfoot clinic visits were more common for families reliant on transportation other than a personal vehicle (P=0.01) and those with annual income under $30,000 (P=0.02). Transportation insecurity was associated with greater social disadvantage as indicated by COI and more missed clinic visits. Level III.

Enhancing last mile connectivity using shared mobility: A stated preference survey of business park commuters

An important step towards more sustainable transport is to reduce the use of private cars. There is a significant unrealized potential of replacing car-based commute with public transportation, especially to and from business parks where many people are co-located, and where the use of private cars are quite common. This study examines the potential of shared mobility solutions to enhance the appeal of public transportation by addressing the last mile challenge. Various types of shared mobility are evaluated and compared in a stated preference survey conducted at the Sluppen business park in Trondheim. Results show that more people may choose the bus if there is a shared mobility solution available to complete the last mile of the commute. The respondents prefer e-scooters if there is no extra cost, but to a lesser degree if they must pay 20NOK. Car commuters who are willing to shift to from car to public transport and shared mobility, are also more willing to both wait and pay extra for a shuttle.

But can it drive to Lapland? A comparison of electric vehicle owners with the general population for identification of attitudes, concerns and barriers related to electric vehicle adoption in Finland

Transportation is a major source of greenhouse gas emissions with private car use accounting for a large proportion of those emissions. Battery powered electric vehicles (EV) are a currently available technology that has the potential to significantly reduce emissions from car use. Therefore, promoting a shift from internal combustion engine vehicles to EVs should be supported by policy makers aiming to curtail emissions from car use. To design policies and interventions to promote EV adoption, information is needed on how people perceive electric vehicles and what are the real and perceived barriers preventing their adoption. With this objective in mind, it was investigated what the current EV owners in Finland are like and how they compare with the general population. We also endeavored to identify real as well as potentially misperceived barriers to EV adoption and factors affecting EV purchasing intentions. The study utilizes a sample of 3857 participants, including 141 electric car owners, who answered a questionnaire investigating lifestyle, car use, environmental and political attitudes as well as household carbon footprint and attitudes towards EVs. EV owners in Finland have more financial security, own more cars, drive more, and have a larger average household carbon footprint than the general population. There are two distinct subgroups among electric car owners, one group being interested in environmental impact of their car use and the other focused on the performance of their cars. People without experience of EVs generally have negative attitudes towards electric cars and also maintain some misconceptions about EVs. Personal experience with electric vehicles is associated with a positive outlook on these types of vehicles and is the strongest predictor of EV purchasing intentions.

Influence factors on travel mode preference of working residents living far away from downtown area on workdays: A hybrid method integrating random parameter logit model and Apriori algorithm

This study presents a detailed analysis on the characteristics of travel mode preference of working residents living far away from downtown area on workdays, using GPS-based activity travel diary data from Shangdi area (Beijing). A hybrid method integrating random parameter logit model with systematic heterogeneity (RPL-SH) and Apriori algorithm is put forward to explore the influence factors and interaction effects affecting travel mode preference. First, the RPL-SH model is established to explore significant factors, and capture the unobserved random heterogeneity and systematic heterogeneity due to individual characteristics on the travel mode preference. Then, these significant factors are used to generate association rules by Apriori algorithm to investigate statistical associations between the specific travel mode preference and these significant factors. Ten significant factors are found in the RPL-SH model, in which annual household income is normally distributed. The results of the Apriori algorithm indicate that some factors combined with other factors could significantly influence working residents’ travel mode preference. For example, the combination of lower annual household income and shorter distance between workplace and the nearest bus stop is highly associated with green travel mode preference. Moreover, the results show that the proposed hybrid method not only demonstrates the consistency of the results of the two methods, but also plays a complementary role in exploring more information on travel mode preference. This research hopes to give regulators a better understanding on how working residents living far away from downtown area choose their travel mode, so as to develop more effective and targeted measures for reducing private car use and alleviating workday traffic congestion.

Overview of Fuel Cell-Hybrid Power Sources Vehicle Technology: A Review

Today, the world suffers from excessive and unfair consumption of non-renewable energy sources, such as high rate of global pollution and global warming. Accordingly, fields of life in general and industry in particular, led by the automobile industry, tended to use clean and renewable energy in industry and consumption to reduce the negative impacts on the global environment. The automotive industry tended to produce electric cars that do not depend at all on traditional energy sources from fossil fuel derivatives. Accordingly, it was necessary to find alternative energy sources that achieve both goals: avoiding the negative impact on the envi-ronment, and producing sufficient energy to achieve the requirements of performance and efficiency from the use of electric cars to be a permanent alternative to traditional cars that run on fossil fuels. This scientific paper provides an overview of one of the versions of modern technology in the field of electric vehicles energy performance to provide the vehicle with energy continuously and the mechanism of control and management in this system. This paper studies the hybrid power sources technology in electric and hybrid cars that depend on a main power source, Fuel Cells (FC), and a secondary power sources, Battery and Ultracapacitor, in the vehicle. This paper presents a brief overview of this system, its components, their characteristics, the advantages of hybridization in this type of energy source with the working mechanism of the system, an overview of the control systems in this technology and a set of challenges facing this type technology and its future perspectives.

Decoding Jakarta Women’s Non-Working Travel-Mode Choice: Insights from Interpretable Machine-Learning Models

Using survey data from three dwelling types in Jakarta, we examine how dwelling type, socioeconomic identity, and commuting distance affect women’s travel-mode choices and motivations behind women’s choices for nearby and distant non-working trips. We compared the performance of the multinomial logit (MNL) model with two machine-learning classifiers, random forest (RF) and XGBoost, using Shapley additive explanations (SHAP) for interpretation. The models’ efficacy varies across different datasets, with XGBoost mostly outperforming other models. The women’s preferred commuting modes varied by dwelling type and trip purpose, but their motives for choosing the nearest activity were similar. Over half of the women rely on private motorized vehicles, with women living in the gated community heavily relying on private cars. For nearby shopping trips, low income and young age discourage women in urban villages (kampungs) and apartment complexes from walking. Women living in gated communities often choose private cars to fulfill household responsibilities, enabling them to access distant options. For nearby leisure, longer commutes discourage walking except for residents of apartment complexes. Car ownership and household responsibilities increase private car use for distant options. SHAP analysis offers practitioners insights into identifying key variables affecting travel-mode choice to design effective targeted interventions that address women’s mobility needs.

Who is ready to live a car-independent lifestyle? A latent class cluster analysis of attitudes towards car ownership and usage

An excessive use of private cars for transportation has multiple negative effects on our society. It is therefore paramount to identify the underlying factors driving car usage among different segments of travellers. In this study, we aim to identify and characterise traveller segments in terms of their car-related attitudes and how different sociodemographic attributes, travel behaviour characteristics (such as using cars as the primary mode of transportation), and the accessibility of their place of residence vary amongst different population segments. Through Confirmatory Factor Analysis and Latent Profile Analysis we identify five different classes, namely car-detractors, −hesitants, −positives, −friends, and −lovers. More favourable car attitudes are associated with higher car ownership and access but, interestingly, there are no significant differences in terms of travel frequency and trip length distribution. This suggests that attitudinal differences relate mostly to modal preference rather than to the underlying travel demand patterns and the associated activities. We also see that car-less individuals are more likely to be car detractors, suggesting that the experiencing barriers for owning a car may contribute to developing more negative attitudes towards cars. Our results shed light on the different influencing factors and characteristics of individuals that consider, or not, a car-centred mobility.

Air pollution and grouping of cities according to their environmental status

In the article, the ecological situation of the cities located in the Kura-Araz plain is analyzed. Our study area is the most populated and most important agricultural region in the country. The possibility of environmental pollution is also high in the area located on the east- west roads. In particular, the pollutants released into the atmosphere were analyzed and the results were determined. During the research, the atmospheric pollution in the cities during the historical period was studied using the mathematical-statistical method. Ecological zoning of cities was carried out using GIS technologies. The main source of air pollution in cities is cars, their number, and the use of outdated cars. Another reason is the important industrial cities located in the study area. Substances released into the air from industrial enterprises pollute the atmosphere of the cities. It was determined that the environmental situation is more intense in cities where large industrial enterprises are located. There are large, medium and small cities in the study area. The main polluting cities are the cities of Mingachevir and Shirvan, which belong to the group of large and medium cities because the most important industrial enterprises of the country are located here. Also, these cities are important power centers of the country. These cities differ from others in terms of population. At the same time, we have included the city of Yevlakh in the group of cities with an important role in atmospheric pollution. As a result of the analysis, ecological zoning of cities was carried out. At this time, 3 gradations were used. During this zoning, the pollution of the atmosphere was taken into account. The influence of carbon monoxide CO2, carbon oxides CHx, nitrogen oxides NOx and sulfur oxides SOx on atmospheric air in cities was analyzed. The main cause of pollution is the location at the intersection of highways. The location on the east-west roads has made the ecological situation in the cities even more tense. Especially in Mingachevir and Shirvan, the environmental situation is more intense.

Conformity Assessment of a Modernised Locomotive Bogie and Body Connection – Type Tests and Results

Referring to the lecture held on 16th Mini-Conference on Vehicle System Dynamics, Identification and Anomalies, Budapest, 5-7 November 2018, the accredited Notified Body started the conformity assessment process of the modernized bogie-locomotive body connection of MÁV-START Class V63 electric locomotives running with Ganz-MÁVAG UFC-type bogies, in 2017. Since the planned modification of the locomotives was delayed, the Conformity Assessment Body could perform the necessary riding quality and noise test in the summer of 2020 instead of September 2018. The study presents the modification carried out on the locomotives, the test procedures, and the test results. The aim and the novelty of the research was to apply the latest developments of the test procedures on a modified, existing rolling stock. The conformity for the new requirement makes challenges for the development of testing even if theoretically a well-known test method is applied. The article gives an example for the application of a classic test method combined with of the new possibilities, that makes unnecessary the use of additional railway test cars.

RESEARCH OF THE COMBUSTION PARAMETERS OF GASOLINE WITH ADDITIONAL HYDROGEN IN A SPARK-IGNITION ENGINE IN EXTERNAL SPEED CHARACTERISTIC MODES

The directions of development and improvement of road transport around the world are inextricably linked to the desire to reduce the use of cars “on traditional fuels” due to limited oil and environmental safety of mankind. Since the modes of external speed characteristic are the most typical for the operation of cars in cities, the study of environmental performance of engines in these modes is an urgent task. Therefore, finding ways to reduce carbon dioxide emissions from automobile engines at high-speed modes is an urgent task. The rapid growth in the number of cars with internal combustion engines and the inevitable decline in world oil reserves necessitate the development and implementation of energy-saving technologies and the use of alternative fuels. Research aimed at finding ways to improve the fuel efficiency and environmental performance of automotive engines is relevant. One of the promising areas is the influence on the combustion process in gasoline engines by using additives of alternative fuels, which include hydrogen. The presented study of the parameters of combustion of gasoline with hydrogen additive in a spark ignition engine at external speed characteristics is a comprehensive analysis of the combustion process of a gasoline-hydrogen mixture and determination of its effect on the concentration of carbon dioxide in exhaust gases by developing a mathematical model that takes into account the composition of the mixture components and features of the combustion process, allows for sufficiently accurate calculation of the operating process of an engine with hydrogen additive at ψ ≤ 10%, its identification by the results of experiments. In the course of the study, dependencies were developed to determine the combustion parameters of the Wiebe model, taking into account the addition of hydrogen to gasoline in the modes of external speed characteristics, and the effect of hydrogen addition on the concentration of CO2 in exhaust gases was analyzed. It is shown that with an increase in the hydrogen additive to 10% by mass fraction to gasoline, there is a decrease in CO2 emissions to almost 30% in the external speed characteristic modes, which corresponds to modern environmental standards for gasoline internal combustion engines.

Cargo bikes for personal transport: A user segmentation based on motivations for use

Building on the success of e-bikes, sales of e-cargo bikes are rapidly increasing in several countries. Cargo bikes fill an important gap in the urban transport market by combining the advantages of cycling with the greater transport capacity of a family car. Whereas most research on cargo bikes has focused on logistics, this paper addresses their use for personal transport. It is based on a large-scale survey in Switzerland among both proprietary cargo bike owners (CBO) and users of cargo bike sharing (CBS) (N = 955). A principal component analysis finds 3 families of motivations for using cargo bikes: transporting children, staying active, and reducing car use. Based on these 3 components, we use hierarchical clustering to identify 4 user segments: cargo transporters, enthusiasts, multimodals, and sustainable parents. Our results suggest that owned and shared cargo bikes are complementary and have the potential to attract new audiences to cycling and reduce car use. They could become a central component in a low-carbon/post-car urban mobility strategy. However, user experiences indicate that lacking safety, road infrastructure and parking provisions remain barriers to wider cargo bike use. We conclude by proposing a future research agenda for cargo bike research.