An investigation of the effects of the common cold on simulated driving performance and detection of collisions

The aim of the present research was to investigate whether individuals with a common cold showed impaired ability on a simulated driving task and the ability to detect potential collisions between moving objects. The study involved comparison of a healthy group with a group with colds. These scores were adjusted for individual differences by collecting further data when both groups were healthy and using these scores as covariates. On both occasions volunteers rated their symptoms, carried out a laboratory task measuring collision detection and also a simulated driving session. Twenty five students from the University of Leeds. 10 volunteers were healthy on both occasions and 15 had a cold on the first session and were healthy on the second. In the collision detection task the main outcomes were correct detections and response to a secondary identification task. In the simulated driving task the outcomes were: speed; lateral control; gap acceptance; overtaking behaviour; car following; vigilance and traffic light violations. Those with a cold detected fewer collisions and had a higher divided attention error than those who were healthy. Many basic driving skills were unimpaired by the illness. However, those with a cold were slower at responding to unexpected events and drove closer to the car in front. The finding that having a common cold reduces the ability to detect collisions and respond quickly to unexpected events is of practical importance. Further research is now required to examine the efficacy of information campaigns and countermeasures such as caffeine

The validity of a low-cost simulator for the assessment of the effects of in-vehicle information systems

This study explored the validity of using a low-cost simulator for the assessment of driver distraction arising from the use of an in-vehicle information system. Eighteen participants drove on a rural road whilst carrying out distractor tasks of various levels of difficulty, in both a low-cost simulator (with gaming console steering wheel and pedals with single monitor display) and a medium-cost one (fixed-base, complete vehicle cab, wrap-around visuals). The distractor tasks were presented at identical locations in each of the drives and an identical suite of driver performance and subjective rating measures were elicited to allow a robust comparison between the two simulator environments. As expected, there was a reduction in mean speed when drivers were completing the distraction tasks and this effect was observed in both simulators. However, drivers spent more time at shorter headways in the low-cost version and demonstrated more erratic steering behaviour in the low-cost version. This could be due to a reduced peripheral view and inferior kinaesthetic feedback through the driver controls, but low-cost simulators could play a significant role in the early stages of design and evaluation of in-vehicle information systems

The existence and impact of the Psychological Refractory Period effect in the driving environment

Driver distraction from in-vehicle tasks can have negative impacts on longitudinal and lateral vehicle control. The distraction problem is increasing due to advances in the functionality, availability, and number of in-vehicle systems. One approach to a solution is managing in-vehicle task presentation to reduce associated distraction. This paper reports three driving simulator experiments, designed to investigate the existence of the Psychological Refractory Period in the driving context and its effect on driver performance. The first two studies demonstrate that the effect is present when one or two surrogate in-vehicle tasks are presented in close temporal proximity to a lead vehicle braking event. Brake responding is subject to an increasing delay as the interval to an in-vehicle task is decreased. In-vehicle task modality and task presentation order modulate this effect. The final study will investigate whether the Psychological Refractory Period exists for a range of safety-critical driving events such as lead vehicle decelerations, swerving away from an out-of-control vehicle, and performing a lane-change manoeuvre. The advances on prior work include the use of an advanced driving simulator, and presentation of unpredictable safety-critical events and real-world in-vehicle tasks. The results have implications for the management of in-vehicle distractions – and driver safety; specifically through controlling the timing and modality of task presentation

Designing an in-vehicle eco-driving support system to assist drivers in conserving fuel

Environmentally friendly driving – or eco-driving – refers to the driving of a vehicle in a way that conserves fuel and reduces emissions. Large fuel savings are possible by targeting the role of driver behaviour in the protection of the environment, and teaching them how to ‘eco-drive’. This study forms part of the ecoDriver project, which aims to develop an in-vehicle eco-driving support system. While many current systems offer after-trip feedback on the fuel efficiency of driving or simple in-trip recommendations (e.g. gear shift indicators), this study investigates a number of systems that provide real-time, feed-forward guidance on how to alter accelerator usage in the upcoming moments to minimise fuel consumption. A driving simulator was used to test three potential eco-driving interfaces which used a common eco-driving guidance algorithm. Two systems used a haptic accelerator pedal, while one presented multi-modal visual and auditory information. Objective eco-driving performance was measured as the error between desired accelerator position defined by the system and accelerator position selected by the driver. Subjective feedback on workload and acceptability of the system was analysed and driver visual distraction was monitored throughout. This study informs on the most effective and acceptable presentation methods for real-time in-vehicle guidance on eco-driving

Design characteristics of a workload manager to aid drivers in safety-critical situations

The objective of this study was to evaluate a workload manager designed to supervise the presentation of in-vehicle information for two age groups of drivers during safety-critical situations. The benefits of a workload manager were compared in various dual-task conditions involving a preceding or a concurrent in-vehicle alert during critical traffic situations. Objective measures such as drivers’ brake response times and secondary task response times as well as subjective measures of driver workload were used. Although older drivers performed worse in the dual task scenario with longer response times and poorer performance on the secondary task in comparison to the younger drivers, results indicated that both age groups benefited from the implementation of a workload manager. There was a consistent trend of improved driving and secondary task performance when the workload manager delayed non-critical information during safety-critical situations, indicating benefits for some otherwise distracted drivers. Implications for the design of a workload manager are discussed

Evaluating the effects of bilingual traffic signs on driver performance and safety

Variable Message Signs (VMS) can provide immediate and relevant information to road users and bilingual VMS can provide great flexibility in countries where a significant proportion of the population speak an alternative language to the majority. The study reported here evaluates the effect of various bilingual VMS configurations on driver behaviour and safety. The aim of the study was to determine whether or not the visual distraction associated with bilingual VMS signs of different configurations (length, complexity) impacted on driving performance. A driving simulator was used to allow full control over the scenarios, road environment and sign configuration and both longitudinal and lateral driver performance was assessed. Drivers were able to read one and two-line monolingual signs and two-line bilingual signs without disruption to their driving behaviour. However, drivers significantly reduced their speed in order to read four-line monolingual and four-line bilingual signs, accompanied by an increase in headway to the vehicle in front. This implies that drivers are possibly reading the irrelevant text on the bilingual sign and various methods for reducing this effect are discussed

The activation of eco-driving mental models: can text messages prime drivers to use their existing knowledge and skills?

Eco-driving campaigns have traditionally assumed that drivers lack the necessary knowledge and skills and that this is something that needs rectifying. Therefore, many support systems have been designed to closely guide drivers and fine-tune their proficiency. However, research suggests that drivers already possess a substantial amount of the necessary knowledge and skills regarding eco-driving. In previous studies, participants used these effectively when they were explicitly asked to drive fuel-efficiently. In contrast, they used their safe driving skills when they were instructed to drive as they would normally. Hence, it is assumed that many drivers choose not to engage purposefully in eco-driving in their everyday lives. The aim of the current study was to investigate the effect of simple, periodic text messages (nine messages in 2 weeks) on drivers’ eco- and safe driving performance. It was hypothesised that provision of eco-driving primes and advice would encourage the activation of their eco-driving mental models and that comparable safety primes increase driving safety. For this purpose, a driving simulator experiment was conducted. All participants performed a pre-test drive and were then randomly divided into four groups, which received different interventions. For a period of 2 weeks, one group received text messages with eco-driving primes and another group received safety primes. A third group received advice messages on how to eco-drive. The fourth group were instructed by the experimenter to drive fuel-efficiently, immediately before driving, with no text message intervention. A post-test drive measured behavioural changes in scenarios deemed relevant to eco- and safe driving. The results suggest that the eco-driving prime and advice text messages did not have the desired effect. In comparison, asking drivers to drive fuel-efficiently led to eco-driving behaviours. These outcomes demonstrate the difficulty in changing ingrained habits. Future research is needed to strengthen such messages or activate existing knowledge and skills in other ways, so driver behaviour can be changed in cost-efficient ways

Drivers’ ability to learn eco-driving skills; effects on fuel efficient and safe driving behaviour

Whilst driving is inherently a safety-critical task, awareness of fuel-efficient driving techniques has gained popularity in both the public and commercial domains. Green driving, whether motivated by financial or environmental savings, has the potential to reduce the production of greenhouse gases by a significant amount. This paper focusses on the interaction between the driver and their vehicle – what type of eco-driving information is easy to use and learn whilst not compromising safety. A simulator study evaluated both visual and haptic eco-driving feedback systems in the context of hill driving. The ability of drivers to accurately follow the advice, as well as their propensity to prioritise it over safe driving was investigated. We found that any type of eco-driving advice improved performance and whilst continuous real-time visual feedback proved to be the most effective, this modality obviously reduces attention to the forward view and increases subjective workload. On the other hand, the haptic force system had little effect on reported workload, but was less effective that the visual system. A compromise may be a hybrid system that adapts to drivers’ performance on an on-going basis