Currently, almost 40 000 people are killed every year on EU roads. About 6 500 of them are drivers and passengers of powered two-wheelers (PTWs), i.e. motorcycles and mopeds. Motorcycle or moped travel carries a risk of death per kilometre travelled 20 times higher than that for car travel. PTW accidents now represent a major subject for road safety in Europe. The safety of vulnerable road users, including motorcycle and moped riders, is one of the priorities of the European Community.
Developing countries have a much lower level of motorisation and the road usage pattern is significantly different from those of developed ones. The proportion of PTWs in these countries is extremely high and the traffic usage patterns are very complex. In India, for instance, PTWs account for about 80% of the domestic automotive sales. This means that these countries are exposed to a much higher level of road accident risk. Typically about 39% of the annual 336 000 road traffic deaths in South East Asia are PTW users.
India's automotive policy (2002-2010) has given a major thrust to improving the road infrastructure, which is abysmally poor in comparison to the growth of traffic (7-10% per annum). While this will largely help in decongesting the roads and reducing the probability of accident occurrence, the motor vehicle rules are being continuously improved to enhance the design of vehicles for safety.
PTWs are single track vehicles, which means that the rider has a more difficult vehicle to control in relation to a car, in particular when cornering or braking, and even more so in emergency situations. Only a few (high-end) motorcycle brands are fitted with ABS and (partly) combined braking systems. Optimization of the PTW brake performance will reduce the impact speed in case an accident cannot be avoided and this will directly reduce the fatality rate and injury level.
The aim of this project was to develop and use new technologies to provide integrated safety systems for a range of Powered Two Wheelers. The systems were developed, in order to improve primary safety and so that they could be linked to secondary safety devices. The project aimed to develop reliable and fail-safe systems which offer improved safety.
The rationale for the PISa project was that the research would contribute to the general EU target of 50% reduction in road accident fatalities; the PISa objectives were aligned with this ambition. PISa also contributed to India’s automotive policy by enhancing the safety of PTW designs.
The quantified objectives for the integrated system were to combine sensors and an advanced braking and suspension system to:
- Avoid 50% of accidents where a collision was not inevitable;
- Reduce the impact speed, and hence reduce the injury severity by one MAIS integer for 50% of accidents where a collision was inevitable;
- Prevent 50% of the single vehicle loss of control accidents.
Scientific and technical objectives:
- Identify the most frequent causes - precipitating factors and contributory factors - of PTW accidents and how the rider interacted with the PTW during the pre-crash phase by analysing PTW accident data and video tapes recorded at dangerous junctions.
- Examine rider and bike interaction when riding along known accident sites using an instrumented PTW.
- Assess and measure rider behaviour in dangerous manoeuvres identified from the accident analysis and instrumented PTW by using computer models, including human muscle activity, that replicate the interaction between a rider and a PTW.
- Assess and measure the PTW behaviour and response in dangerous manoeuvres, identify potential areas for improvement by use of triggered control mechanisms on for instance suspension, brakes, steering.
- Identify existing technologies and safety systems in passenger cars and assess their usability in PTWs.
- Develop a PTW safety system that integrates sensors, warning devices – visual, acoustic, and/or mechanical – an intelligent braking system and automatically variable suspension that will reduce the incidence and severity of PTW accidents.
- Assess the costs of the PTW safety system and the benefits in terms of reduction in accidents and injuries.
- Fit the prototype integrated safety sy
The PISa project developed advanced integrated safety systems similar to those fitted to cars. These comprise sensors to detect a potential emergency, an advanced braking and suspension system that will respond to inputs from the sensors and warning devices to assist the rider. The systems take into account human reaction to information, warning and support systems. The (pre-crash) sensors could be linked to a black box that fires an airbag or other passive safety devices when the system has decided that crash avoidance is not possible, thus creating a genuine integrated safety system.
The system components include sensors, a PTW state estimator, logic control, warning devices, and advanced/intelligent actuators within brakes and suspensions elements to assist the rider. Specific sensors and actuators are developed and integrated into an operational safety system for PTWs to allow for driver warning and assistance and to improve handling and stability, to be innovative and beyond current state-of-the-art. The developed systems are then implemented in PTWs and evaluated by executing road and track tests and performing simulations. The cost savings in terms of reduction in accidents and injuries will be related to the costs of fitting the integrated safety systems to PTWs.
The Objectives of WP2 and WP3 were met.
The results of WP6 showed that the PISa system was predicted to deliver significant casualty reductions although the extent to which these address the accident and casualty reduction targets set by the PISa project was difficult to assess. The tests within the PISa project focussed on system validation with consideration of system evaluation. Although these tests showed that the system had the potential to function as intended and demonstrated good performance improvements in specific, 'uncluttered' test conditions, the test results could not be related to real-world system effectiveness. This was because insufficient information exists with which to robustly define the system effectiveness at the level required to perform a full cost benefit analysis. This was for a variety of reasons:
- Information relating to the chronology of accident events are missing from the retrospective accident data, meaning that the magnitude of performance increase provided by the system cannot be objectively defined.
- Information on how the systems perform on other, more representative PTWs, is unknown.
- The real-world effectiveness is influenced by the rider. The PISa testing used test riders who were informed about the types of test being conducted. Therefore, no data is available regarding how riders of different ages, levels of experience, gender or attitude react to the PISa systems in 'on-the road' conditions, or whether the systems have different levels of effectiveness for different users.
- For those systems were the performance can be directly compared to what the rider did in an accident situation (for example the braking performance for CB), while the results suggest that the impact speed can be reduced by approximately 18.5%, the effect on injury outcome cannot be objectively estimated. This is because the impact object and rider kinematics and trajectory are unpredictable and no injury risk functions exist with which to quantify the effect on injury level of reducing the impact speed, although the overall effect of reducing the impact energy is of course theoretically beneficial.
For these reasons it proved very difficult to extrapolate the track performance to a larger accident population. This, coupled with the fact that the system was focussed on accident mitigation (and not avoidance) made estimation of the injury benefits difficult. However, the EU-27 target populations (numbers of PTW casualties who could be i
Technological developments have been made in parallel to PISa by vehicle manufacturers and other EC and national funded projects, such as ABS, combined and traction control. These systems are now available as an option on many, and as standard on some, premium motorcycle models. This means that as these systems are becoming more common in the fleet and market penetration improves, the braking technologies proposed and developed within PISa are becoming more widely feasible in terms of implementation and cost. This is a more positive situation than was the case when the PISa project was proposed. Furthermore, mandatory fitment of ABS or CBS is currently being considered by the EC for new PTWs.
The PISa project made a good contribution to industry and policy makers as it has provided a demonstration that the Integrated Safety technologies can be combined and integrated successfully. Furthermore, the PISa project has defined a range of PTW accident countermeasures based on a sample of European accidents. This provides important accident causation information and could be used by the research community or by policy makers to target the most effective strategies to reduce European PTW accidents.