Applications of the theory of planned behaviour to drivers' speeding behaviour

The theory of planned behaviour (TPB; Ajzen, 1985, 1988, 1991) provides apotentially useful approach for investigating the links between drivers' attitudes andbehaviour and for informing road safety interventions that aim to promote 'safe' driving. This paper presents a review of previous research studies in which the TPBhas been applied to drivers'speeding behaviour. Some conceptual andmethodological limitations of the studies are raised. We then summarise two studiesthat we have recently conducted to overcome these limitations and discuss theimplications for road safety

Effects of low speed limits on freeway traffic flow

Recent years have seen a renewed interest in Variable Speed Limit (VSL) strategies. New opportunities for VSL as a freeway metering mechanism or a homogenization scheme to reduce speed differences and lane changing maneuvers are being explored. This paper examines both the macroscopic and microscopic effects of different speed limits on a traffic stream, especially when adopting low speed limits. To that end, data from a VSL experiment carried out on a freeway in Spain are used. Data include vehicle counts, speeds and occupancy per lane, as well as lane changing rates for three days, each with a different fixed speed limit (80 km/h, 60 km/h, and 40km/h). Results reveal some of the mechanisms through which VSL affects traffic performance, specifically the flow and speed distribution across lanes, as well as the ensuing lane changing maneuvers. It is confirmed that the lower the speed limit, the higher the occupancy to achieve a given flow. This result has been observed even for relatively high flows and low speed limits. For instance, a stable flow of 1942 veh/h/lane has been measured with the 40 km/h speed limit in force. The corresponding occupancy was 33%, doubling the typical occupancy for this flow in the absence of speed limits. This means that VSL strategies aiming to restrict the mainline flow on a freeway by using low speed limits will need to be applied carefully, avoiding conditions as the ones presented here, where speed limits have a reduced ability to limit flows. On the other hand, VSL strategies trying to get the most from the increased vehicle storage capacity of freeways under low speed limits might be rather promising. Additionally, results show that lower speed limits increase the speed differences across lanes for moderate demands. This, in turn, also increases the lane changing rate. This means that VSL strategies aiming to homogenize traffic and reduce lane changing activity might not be successful when adopting such low speed limits. In contrast, lower speed limits widen the range of flows under uniform lane flow distributions, so that, even for moderate to low demands, the under-utilization of any lane is avoided. These findings are useful for the development of better traffic models that are able to emulate these effects. Moreover, they are crucial for the implementation and assessment of VSL strategies and other traffic control algorithms.Peer ReviewedPostprint (published version

Mitigating blind spot collision utilizing ultrasonic gap perimeter sensor

Failure to identify the vehicle by the side of the vehicle or in other word as blind spot area, especially larger vehicles are one of the causes of the accident. For some drivers, the simple solution is to place an additional side mirror. However, it is not the best solution because this additional side mirrors do not provide an accurate picture of actual or estimated distance to the object or another vehicle. The objective of this project is to identify the causes of automobile collisions, notably the side collision impact causes by the blind spot, to develop a system that can detect the presence vehicles on the side and to develop a system that are affordable for normal car users. To achieve this objective, flow chart was designed to help write coding using Arduino 1.0.2 and design hardware. This system can detect the obstacle within range 2cm to 320cm from the edge of the project vehicle. Before this system developed, the survey was conducted to determine what the driver wants. After that, the design process is carried out. The input to this system is Ping ultrasonic sensor, LCD, LED, and siren for the output part. LCD and LED were displaying the distance from the vehicle and the siren will be switched on to warn the driver when have obstacle in the blind spot area. As a conclusion, the Mitigating Blind Spot Collision Utilizing Ultrasonic Gap Perimeter Sensor System has successfully completed. This system able to detect the presence of other vehicles on the side of the project vehicle, especially in the blind spot area and will alert the driver when the vehicle is nearby when the alarm system is operated. The efficiency of this system to detect objects in the blind spot area is 79.82%. Others, it will give the display value less than one second after obstacle exists in front of the sensor. This operating time is most important because if the system is slow, the main function of this system to detect the obstacle in the blind spot area is not achieved

Personality traits and beliefs about peers\u2019 on-road behaviors as predictors of adolescents\u2019 moped-riding profiles.

Several efforts aimed at discriminating between different degrees of on-road risky attitudes have been devoted to the identification of personality profiles among young drivers. However, the results are often inconsistent because of the limits of selfreport measures. To overcome these limits, we tried to identify different profiles based on our study participants\u2019 driving performances in a virtual environment and to look for psychological predictors of inclusion in one of three profiles. One-hundred and fourteen inexperienced adolescents were involved in this study, which included two experimental sessions. During the first, before riding along five virtual courses on a moped simulator, participants\u2019 sensation seeking, locus of control, aggressiveness and beliefs about their peers\u2019 on-road behaviors were measured by means of self-report tools. During the second session, the participants drove the simulator along six courses that were different from those faced in the first session. A cluster analysis was run on a wide number of indexes extracted from the participants\u2019 performances to detect different riding profiles. Three profiles emerged (Imprudent, Prudent and Insecure), with specific riding patterns. The profiles also differed in terms of riding safety, assessed by means of the scores automatically given by the simulator to the participants\u2019 performances. Reporting an external locus of control, underestimating peers\u2019 on-road risky behaviors and showing less concern for fate among the possible causes of crashes are predictors that increase the risk of being included in the Imprudent profile. Low levels of dangerous thrill seeking predict inclusion in the Prudent profile, whereas high rates of self-reported anger play a role in discriminating the Insecure riders from the other profiles. The study indicates that it is possible to identify riding profiles with different degrees of on-road safety among inexperienced adolescents by means of simulated road environments. Moreover, inclusion in these profiles is predicted by different patterns of personality variables and beliefs. Further research is needed to verify the validity of these conclusions in real road conditions

The effects of speed cameras: How drivers respond

This study set out to examine the effects and effectiveness of various strategies related to the deployment of speed cameras, and to explore how different types of driver responded to cameras and perceived their operation. Recommendations for best deployment were to be considered. It was carried out between 1993 and 1996 after the Road Traffic Act 1991 authorised the use of automatic speed devices for the detection of offences. A series of 12 surveys arranged in five sets and having some cross-sectional and some longitudinal elements was undertaken together with some depth interviews, and self-report measures predominated. Five police forces helped to set up the research. In total 6879 drivers took part. The particular interventions focused upon comprised camera signing alone; two kinds of publicity campaign linked with speed camera deployment; prosecution following detection by speed camera; and the effects of cameras when first installed and over time.The Department of Environment, Transport and the Regions

Response to automatic speed control in urban areas: A simulator study.

Speed affects both the likelihood and severity of an accident. Attempts to reduce speed have centred around road design and traffic calming, enforcement and feedback techniques and public awareness campaigns. However, although these techniques have met with some success, they can be both costly and context specific. No single measure has proved to be a generic countermeasure effective in reducing speed, leading to the suggestion that speed needs to be controlled at the source, i.e. within the vehicle. An experiment carried out on the University of Leeds Advanced Driving Simulator evaluated the effects of speed limiters on driver behavionr. Safety was measured using following behaviour, gap acceptance and traffic violations, whilst subjective mental workload was recorded using the NASA RTLX. It was found that although safety benefits were observed in terms of lower speeds, longer headways and fewer traffic light violations, drivers compensated for loss of time by exhibiting riskier gap acceptance behaviour and delayed braking behaviour. When speed limited, drivers' self-reports indicated that their driving performance improved and less physical effort was required, but that they also experienced increases in feelings of frustration and time pressure. It is discussed that there is a need for a total integrated assessment of the long term effects of speed limiters on safety, costs, energy, pollution, noise, in addition to investigation of issues of acceptability by users and car manufacturers

Sensation seeking, non-contextual decision making, and driving abilities as measured through a moped simulator.

The general aim of the present study was to explore the relations between driving style (assessed through a moped riding simulator) and psychological variables such as sensation seeking and decision making. Because the influences of sensation seeking and decision making on driving styles have been studied separately in the literature, we have tried to investigate their mutual relations so as to include them in a more integrated framework. Participants rode the Honda Riding Trainer (HRT) simulator, filled in the Sensation Seeking Scale V (SSS V), and performed the Iowa Gambling Task (IGT). A cluster analysis of the HRT riding indexes identified three groups: Prudent, Imprudent, and Insecure riders. First, the results showed that Insecure males seek thrills and adventure less than both Prudent males and Insecure females, whereas Prudent females are less disinhibited than both Prudent males and Insecure females. Moreover, concerning the relations among SSS, decision making as measured by the IGT, and riding performance, high thrill and adventure seekers performed worse in the simulator only if they were also bad decision makers, indicating that these two traits jointly contribute to the quality of riding performance. From an applied perspective, these results also provide useful information for the development of protocols for assessing driving abilities among novice road users. Indeed, the relation between risk proneness and riding style may allow for the identification of road-user populations who require specific training