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

Smart driving aids and their effects on driving performance and driver distraction

In-vehicle information systems have been shown to increase driver workload and cause distraction; both of which are causal factors for accidents. This simulator study evaluates the impact that two designs for a smart driving aid, and scenario complexity have on workload, distraction and driving performance. Results showed that real-time delivery of smart driving information did not increase driver workload or adversely effect driver distraction, while having the effect of decreasing mean driving speed in both the simple and complex driving scenarios. Subjective workload was shown to increase with task difficulty, as well as revealing important differences between the two interface designs

Smart driving assistance systems : designing and evaluating ecological and conventional displays

In-vehicle information systems have been shown to increase driver workload and cause distraction; both are causal factors for accidents. This simulator study evaluates the impact that two designs for a smart driving aid and scenario complexity has on workload, distraction and driving performance. Results showed that real-time delivery of smart driving information did not increase driver workload or adversely affect driver distraction, while having the effect of decreasing mean driving speed in both the simple and complex driving scenarios. Important differences were also highlighted between conventional and ecologically designed smart driving interfaces with respect to subjective workload and peripheral detection

Would those who need ISA, use it? Investigating the relationship between drivers' speed choice and their use of a voluntary ISA system

Intelligent Speed Adaptation (ISA) is one of the most promising new technologies for reducing the prevalence and severity of speed-related accidents. Such a system could be implemented in a number of ways, representing various "levels of control" over the driver. An ISA system could be purely advisory or could actually control the maximum speed of a vehicle. A compromise would be to introduce a system that allows a driver to choose when to engage ISA, thus creating a “voluntary” system. Whilst these voluntary systems are considered more acceptable by drivers, they will not offer safety benefits if they are not used by the driver. Two studies were carried out that examined the relationship between drivers’ reported and actual speeding behaviour, their propensity to engage a voluntary ISA system and their attitudes towards such a system. These studies were carried out in a driving simulator and in an instrumented vehicle. In both the studies, drivers’ propensity to exceed the speed limit was lowered when ISA was available but this effect was confined to the lower speed limits. In general, drivers engaged ISA for approximately half of their driving time, depending on the speed limit of the road and indeed, on the nature of the road and the surrounding traffic. This was particularly true in the field study where drivers were more inclined to “keep up with” the surrounding traffic. The results from the on-road study indicated that those drivers who considered ISA to be both a useful and pleasant system, were overall more likely to engage it. However, those drivers who confessed to enjoying exceeding the speed limit were less likely to use ISA. This is an important finding when considering the mechanisms for implementing ISA: those drivers who would benefit most would be less likely to use a voluntary system

Professional Driver Training and Driver Stress: Effects on Simulated Driving Performance

Book chapter from Traffic and Transport Psychology, edited by G. Underwood, published by Elsevier, 2005

Network effects of intelligent speed adaptation systems

Intelligent Speed Adaptation (ISA) systems use in-vehicle electronic devices to enable the speed of vehicles to be regulated externally. They are increasingly appreciated as a flexible method for speed management and control, particularly in urban areas. On-road trials using a small numbers of ISA equipped vehicles have been carried out in Sweden, the Netherlands, Spain and the UK. This paper describes the developments made to enhance a traffic microsimulation model in order to represent ISA implemented across a network and their impact on the networks. The simulation modelling of the control system is carried out on a real-world urban network, and the impacts on traffic congestion, speed distribution and the environment assessed. The results show that ISA systems are more effective in less congested traffic conditions. Momentary high speeds in traffic are effectively suppressed, resulting in a reduction in speed variation which is likely to have a positive impact on safety. Whilst ISA reduces excessive traffic speeds in the network, it does not affect average journey times. In particular, the total vehicle-hours travelling at speeds below 10 km/hr have not changed, indicating that the speed control had not induced more slow-moving queues to the network. A significant, eight percent, reduction in fuel consumption was found with full ISA penetration. These results are in accordance with those from field trials and they provide the basis for cost-benefit analyses on introducing ISA into the vehicle fleet. Contrary to earlier findings from the Swedish ISA road trials, these network simulations showed that ISA had no significant effect on emission of gaseous pollutants CO, NOx and HC. Further research is planned to investigate the impact on emission with a more comprehensive and up to date modal emission factor database

The Leeds Advanced Driving Simulator: Three Years In Operation

The Leeds Advanced Driving Simulator (LADS) at the University of Leeds is a medium cost fixed-base simulator and its development has been funded by the Science and Engineering Research Council (now EPSRC). It has been fully operational since mid-1993 for rural-road scenes (Carsten and Gallimore, 1993) but currently simulation of urban environments and vehicle interactions are possible too. This paper focuses on the recent development of LADS. Also detailed other recent research projects carried out in the simulator to date

The Leeds Advanced Driving Simulator: Three Years In Operation

The Leeds Advanced Driving Simulator (LADS) at the University of Leeds is a medium cost fixed-base simulator and its development has been funded by the Science and Engineering Research Council (now EPSRC). It has been fully operational since mid-1993 for rural-road scenes (Carsten and Gallimore, 1993) but currently simulation of urban environments and vehicle interactions are possible too. This paper focuses on the recent development of LADS. Also detailed other recent research projects carried out in the simulator to date

Safe driving in a green world : a review of driver performance benchmarks and technologies to support ‘smart’ driving

Road transport is a significant source of both safety and environmental concerns. With climate change and fuel prices increasingly prominent on social and political agendas, many drivers are turning their thoughts to fuel efficient or ‘green’ (i.e., environmentally friendly) driving practices. Many vehicle manufacturers are satisfying this demand by offering green driving feedback or advice tools. However, there is a legitimate concern regarding the effects of such devices on road safety – both from the point of view of change in driving styles, as well as potential distraction caused by the in-vehicle feedback. In this paper, we appraise the benchmarks for safe and green driving, concluding that whilst they largely overlap, there are some specific circumstances in which the goals are in conflict. We go on to review current and emerging in-vehicle information systems which purport to affect safe and/or green driving, and discuss some fundamental ergonomics principles for the design of such devices. The results of the review are being used in the Foot-LITE project, aimed at developing a system to encourage ‘smart’ – that is safe and green – driving