Psychological Factors Influencing Speeding Intentions of Car Drivers and Motorcycle Riders in Urban Road Environments

The aim of this study was to examine and compare psychological factors influencing car drivers’ and motorcycle riders’ speeding intentions (IN), using the Theory of Planned Behaviour (TPB). The psychological factors modules included Attitude (AT), Subjective Norm (SN) and Perceived Behavioural Control (PBC). These were employed to explain speeding intentions in urban road environments. A sample of 188 car drivers and 174 motorcycle riders were collected from the two universities within Khon Kaen, Thailand. The Structural Equation Model (SEM) was used to examine and explain speeding intentions. The results indicated that the TPB could explain 33% and 41% of the variance of intentions by car drivers and motorcycle riders, respectively. The most significant psychological factor for car drivers was determined by attitude (AT), while the speeding intention of motorcycle riders was attributed to perceived behavioural control (PBC). The authorities in Khon Kaen Province should determine safety policies that can improve these psychological factors, which could have various effects or outcomes on changing car drivers’ and motorcycle riders’ speeding intentions. The outcome of this study could help to understand car drivers’ and motorcycle riders’ speeding intentions in urban road environments and it could be useful for development of safety measures

Cross-cultural Differences in Speeding Intentions of Drivers on Urban Road Environments in Asian Developing Countries

The aim of this study was to examine and compare the psychological factors influencing driver speeding behavior in 3 cities in Southeast Asia, focusing on developing counties, using the Theory of Planned Behaviour (TPB). Data was collected from 570 respondents in the urban areas of Khon Kaen in Thailand, Vientiane in Laos and Phnom Penh in Cambodia. The psychological factors of TPB include attitude (AT), subjective norm (SN) and perceived behavioral control (PBC). These factors were employed to explain speeding intentions in urban road environments. The Structural Equation Models (SEM) was used to examine and explain speeding intentions. The results indicated that the TPB could explain the variance by intentions of drivers in Khon Kaen, Vientiane and Phnom Penh at 33%, 46%, and 84%, respectively. The most significant of the psychological factors for Khon Kaen drivers was determined by AT, while the speeding intentions of Vientiane drivers and Phnom Penh drivers were determined by PBC. From this data, the authorities of each city should create and implement safety policies that can improve these psychological factors, which could have a positive effect on drivers’speeding intentions in urban road environments. The outcome of this study could be useful for understanding the speeding attitudes of drivers in three different countries and would be beneficial for the development and introduction of preventative safety measures in these countries as well

An evaluation of speed limit measure: A case of the Mittraphap highway passing through Khon Kaen city

The objective of this study is to evaluate the speed control measure on the arterial road of Khon Kaen city. The 60 km/hr speed limit was posted on the urban arterial since 2012. To reveal the existing conditions, this study analyzed the accident data, speed data and enforcement data. Driver’s and government officer’s attitudes toward the existing speed control measures are captured through the questionnaires survey and interview processes, respectively. The study results reveal that under the existing road environment, the drivers disagree with the posted 60 km/h speed limit and it cannot be enforced by the police. However, 1-year of speed control program significantly reduces the number of traffic injuries and fatalities. Spot speed study revealed that most of drivers reduced their speed once they saw the police with the radar gun. 86% of drivers agree with the speed control measure and 93% of drivers aware that driving speed is related to safety. Therefore, to support the existing speed control measure, this study suggests that the responsible authorities should consider and study for the suitable speed limit for the area and modify the road geometries accordingly. Besides, installing automatic speed enforcement devices, and continuing public campaign directly to the risk groups could also increase the effectiveness of the program

A study of speed limits and speed control measures for the urban arterial road

Speed limits in accordance with environment and road functions have been used as a fundamental tool for speed management and road safety. This paper presents literatures review of speed limits measure and results from the study on speed limits problem and driver attitude toward the speed limit and speed control measure. Area of study is on the arterial road where the Mittaprab Highway passed through Khon Kaen City. The study found that improper designation of road functions is the main cause of complexity and difficulty on safety management. It suggests more researches on speed limit setting methods to accommodate the road conditions of the country. In order to increase effectiveness of speed limits measure, this paper suggests transportation-related authorities to classify this area to be the urban arterial road, to set proper speed limits, and to modify the road environment in accordance with its function. More measures to enhance speed limit effectiveness and to reduce accident are included automatic speed control devices, speed limits warning signs, and advertisement signs to use the bypass route. These could enhance the effective speed management program

Development of a Real-World Eco-Driving Cycle for Motorcycles

Climate change is a major issue all around the world. The transportation industry currently accounts for most CO2 emissions. The goal of this research is to develop a real-world eco-driving cycle for internal combustion engine motorcycles that can reduce fuel consumption and CO2 emissions. This study developed onboard measuring equipment to measure the speed profile and fuel consumption of a motorcycle driving in real time. A total of 78 motorcycle riders rode a test motorcycle with the onboard equipment along a road network to collect real-world data. All of the collected real-world data were analyzed by cluster analysis based on fuel consumption (km/L) to divide riders into two groups, high-fuel-consumption riders and low-fuel-consumption riders. The collected real-world data of the low-fuel-consumption riders were used to develop a real-world eco-driving cycle, whereas the collected real-world data from the high-fuel-consumption riders were used to develop a real-world non-eco-driving cycle. The CO2 emissions were calculated by the speed profiles of the developed driving cycles. The findings reveal that the real-world eco-driving cycle provided a fuel consumption rate 39.3% lower than the real-world non-eco-driving cycle. In addition, the real-world eco-driving cycle provided a CO2 emission rate 17.4% lower than the real-world non-eco-driving cycle. The application of the developed real-world eco-driving cycle for motorcycles is proposed

Motorcycle On-Road Driving Parameters Influencing Fuel Consumption and Emissions on Congested Signalized Urban Corridor

This study aims to find the on-road driving parameters influencing fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor. A motorcycle onboard measurement system was developed to measure instantaneously and continuously record on-road driving data, including speed-time profile, emissions, and fuel consumption, by the second. The test motorcycles were driven by 30 sample motorcyclists on a signalized urban corridor in Khon Kaen City, Thailand, to collect their on-road driving behavior during the morning peak period. Cluster analysis was applied to analyze collected driving data and to categorize the drivers by level of fuel consumption and on-road driver behavior. The on-road driving parameter influencing fuel consumption and emissions was then determined. Results revealed that proportion of idle time significantly influenced fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor, though aggressive driving behavior, hard acceleration and deceleration, did not have the same kind of influence

Effects of automated speed control on speeding intention and behavior on mixed-traffic urban arterial roads

Although the effectiveness of automated speed control (ASC) has been proven, the mechanism of behavioral change in developing countries remains unclear. The objective of this study was to elucidate the effect of ASC on drivers' speeding intention and behavior on mixed-traffic urban arterial roads. Before and during the implementation of ASC, questionnaires based on the theory of planned behavior (TPB) were administered to local passenger-vehicle drivers. A total of 200 participants with an average age of 38.4 years completed both survey waves. To explain the mechanism of behavioral change, the multiple indicators multiple causes (MIMIC) structural equation modeling (SEM) time-invariant was used simultaneously for both waves. The model explained 49% and 55% of the variance in intention, and 40% and 56% of the variance in self-reported speeding behavior, respectively, before and during the ASC implementation period. The findings reveal that ASC altered the cognitive factors of speeding behavior. Speeding became less favorable, had lower approval, and was more difficult to control. Drivers reported lower speeding tendency and diminished speeding behavior. Furthermore, the ASC changed the relative impact of the factors, boosted the influence of family members and close friends on drivers' speeding motivation, and increased the influence of intention and perceived control on speeding behavior. This paper provides recommendations for the implementation of ASCs on mixed-traffic urban arterial roads in developing countries

Vehicle kilometers of travel and fuel consumption rate for estimating CO2 emission of vehicles in Khon Kaen city

The Vehicle Kilometers of Travel (VKT) of each vehicle type can be applied to estimate amount of fuel consumption and CO2 emission from transport sector of nation. The objectives of this study are to survey and develop VKT model, fuel consumption rate of each vehicle type as well as to calculate amount of fuel consumption and CO2 emission from register vehicles in Khon Kaen Province. The target vehicle type includes motorcycle, sedan and pickup truck. The researchers interviewed the drivers by questioning a record of odometer, vehicle age, fuel type and fuel consumption of their vehicles at the gas stations and the bus terminal in Khon Kaen City. The researchers developed the VKT models of each vehicle type, fuel type, and level of driver’s income, presenting a relation between VKT (kilometer) and vehicle age (year), by applying the regression analysis. As the results, the developed VKT models reveal that VKT of all types of vehicle has a high correlation with the age of vehicle as older vehicle has a higher VKT. The ranges of fuel consumption rate of motorcycle and sedan are during 24.7-25.4 and 11.1-11.5 km/l, respectively. The calculated amount of CO2 emitted by targeted vehicles is 494,404 t-CO2/year

Understanding Intention to Use Conditionally Automated Vehicles in Thailand, Based on an Extended Technology Acceptance Model

Automated vehicles (AVs) provide several advantages in solving issues of road traffic; including enhanced safety, reduced greenhouse gas emissions, and reduced traffic congestion. As AVs are still relatively new developments in developing countries, AV adoption faces challenges from both technological and psychological issues. Therefore, our initial research focus is on identifying the factors that influence the intention to use conditionally automated vehicles (CAVs; SAE Level 3). An extended technology acceptance model (TAM), which includes Trust, Perceived Risks, and Environmental concerns, is proposed as the predictor model in this study. The 299 participants gathered through online surveys in Thailand were examined using the Structural Equation Model (SEM) technique. In this study, Trust was shown to be the strongest predictor of Intention, followed by Perceived Ease of Use, whereas Perceived Usefulness had no impact on intention to use the SAE Level 3. The results of this study will be able to guide the forming of future policies that aim at promoting the use of AVs and helping technology developers create systems to better meet the needs of users in developing nations

Understanding Intention to Use Conditionally Automated Vehicles in Thailand, Based on an Extended Technology Acceptance Model

Automated vehicles (AVs) provide several advantages in solving issues of road traffic; including enhanced safety, reduced greenhouse gas emissions, and reduced traffic congestion. As AVs are still relatively new developments in developing countries, AV adoption faces challenges from both technological and psychological issues. Therefore, our initial research focus is on identifying the factors that influence the intention to use conditionally automated vehicles (CAVs; SAE Level 3). An extended technology acceptance model (TAM), which includes Trust, Perceived Risks, and Environmental concerns, is proposed as the predictor model in this study. The 299 participants gathered through online surveys in Thailand were examined using the Structural Equation Model (SEM) technique. In this study, Trust was shown to be the strongest predictor of Intention, followed by Perceived Ease of Use, whereas Perceived Usefulness had no impact on intention to use the SAE Level 3. The results of this study will be able to guide the forming of future policies that aim at promoting the use of AVs and helping technology developers create systems to better meet the needs of users in developing nations