Getting the best brains to support iRAP's road infrastructure safety research.
The iRAP programme is now active in over 70 countries, with links to practitioners in each country. It is an evidence-based programme and the iRAP team is fortunate to work with some of the world's leading researchers and research agencies. This makes iRAP a stimulating and exciting place to be, but it also means that everyone in the team realises that there are a lot of infrastructure road safety questions that still need to be answered!
Working in such a large network means that research questions can be worked on, discussed and shared widely and can very quickly lead to answers being tested and used. Here, we have listed some of issues identified by road authority and research partners around the world who are implementing iRAP assessments.
Please feel free to contribute to this list of research needs or contact iRAP Technical Director, Steve Lawson (
)), if you would like to follow up on some of the issues listed here and start research in these areas. Some of those topics listed here would be suitable as MSc projects for postgraduate students. Other topics could be, or would form part of, much larger research programmes.
iRAP does not currently have the financial resources to fund all the good ideas for work that are presented to it, it but it is often able to engage with and provide know-how to those who want to contribute to research that will contribute to the iRAP vision of a world free of high-risk roads.
Urban area safety & sustainability in LMICs
Globally there is a rapid movement of populations to urban areas in low and middle income countries (LMICs) in particular. With this move comes an increasing safety problem in urban core areas, particularly in relation to the safety of pedestrians, public transport facilities, urban intersections and urban areas. Priority research activities will include:
- An investigation of the distribution of crash types in urban areas including where, when and how road deaths occur on urban roads in LMICs. This would be focused on the overall distribution of injury patterns exists on the urban network of a sample of major cities of LMICs.
- Review of evidence based knowledge in relation to the pedestrian and public transport related countermeasures that work, in what circumstances and the quantification of fatality risk reductions.
- Investigation of mode shift related treatments and safe design practice for the urban environment in relation to sustainable development and transport.
- Influence of Bus Rapid Transit on overall crash rates on urban corridors
- The safety impact of intersection related treatments including intersection signal timings, signal coordination, pedestrian phases, turning treatments and turning bans.
- The effectiveness of one way networks and area based treatments and their effect on speed, crash numbers and fatality rates.
- The role and management of speed and congestion in relation to safety outcomes.
- Crash rates in relation to different roundabout designs and size.
On completion of the research all relevant findings will be incorporated into the iRAP toolkit (http://toolkit.irap.org) and the iRAP star rating and countermeasure generation modules, to ensure that the research in converted into practice immediately.
Star Rating of new designs for all road users
Significant new investment in roads occurs every year across the world. The safety performance of these new investments is often less than desired in particular relation to the needs of vulnerable road users. iRAP is currently working with the development banks to introduce the specification of minimum star rating standards as part of new designs. For example "...the new road shall deliver a minimum three star standard for vehicle occupants, motorcyclists, pedestrians and cyclists at the design operating speed of 30mph".
- Enabling the safety of new or rehabilitated roads to be assessed at various stages of design is a valuable and effective way of communicating and instilling road safety within a project. This project would focus on the following:
- Development of an effective process for the star rating of designs and integration opportunities within existing tools that enable and inform the design process.
- A partnership with AASHTO to investigate the potential inclusion of an estimated star rating as a standard output of IHSDM (Interactive Highway Safety Design Model).
- Inclusion of estimated star ratings as an output measure within typical road design software applications in use around the world.
- Identify opportunities to emphasise safety components within road construction and rehabilitation projects.
Harmonisation of road safety and asset management investment modelling
The detailed management and modelling of pavement assets is well advanced throughout the world. This includes life cycle costing, optimisation of programmes related to capacity and asset preservation and treatment selection. The iRAP model provides similar outcomes for the active management of road safety across a network. The project will:
- Compare available risk and road investment models and examine the compatibility of each and when, where and how assessment measures should be integrated.
- Identify opportunities for the integration of safety and asset management assessment activities that maximize productivity and both safety and asset preservation activities.
- Undertake a detailed case study using, for example, the HDM-4 and iRAP models in a parallel investment assessment to highlight the potential for crash and injury reduction input within existing models.
- Align and/or make compatible countermeasure generation modules within the assessment tools where appropriate and detail where harmonisation is a priority.
Crash data reporting in low and middle income countries
A range of crash data related research outcomes will inform better investment and engineering decision making in low and middle income countries. Fatality data availability is limited with under-reporting common with very little information often available on serious injury data. Key issues to be explored include:
- Assessment of aggregated fatal to serious injury ratios in LMICs.
- Assessment of fatal to serious ratios by road-user type in LMICs.
- Fatal to serious injury ratios and under-reporting variation by road-user type.
- Fatal to serious injury ratios and under-reporting variation by geographical location and road type.
Pedestrian safety in low and middle income countries
The safety of pedestrians is a critical area for improvement over the Decade of Action. The pedestrian star ratings used by iRAP provide an initial benchmark of safety performance and priority improvements that are cost effective. Priority research needs for pedestrians exist in the following areas:
- The safety of efficacy of unsignalised pedestrian crossings and measures needed to modify designs and/or enforce compliance from drivers that are widely seen as abused in LMICs.
- Individual risk of walking alongside roads versus individual risk of crossing roads
- Methods of estimation of pedestrian flow that can be applied in low and middle income countries.
- Effectiveness and key design criteria for pedestrian fencing to control and manage crossing movements and large volumes of pedestrians.
Safety improvement options for vulnerable road users (VRUs)
Around half of road deaths are vulnerable road users. In addition to the pedestrian specific research priorities above a focussed research project on vulnerable users could consider the following issues:
- Risk factors to assess the influence of high percentages of other VRUs (cyclists, motorcyclists, carts) on crash rates. How does this influence modelling of crashes in particular with relation to the "safety in numbers" theories.
- How do motorcycles as a percentage of the flow, as well as absolute numbers, relate to crash risk?
- Cyclist risk - influence of measurable infrastructure variable on risk to cyclists.
- Influence of dedicated motorcycle, cycle facilities on crash rates and the key design features needed for safe operation (width, directional flow, security issues).
- Detailed assessment of road barrier design options in relation to motorcycle-friendly performance and expected injury outcomes at various speeds.
- Update of iRAP Star Rating models for Bicycle and Motorcycle users and associated countermeasures in the iRAP Safer Roads Investment Plan.
Detailed review of countermeasure effectiveness
The applicability and transferability of crash modification factors and related countermeasure effectiveness is important to ensure crash models reflect operating conditions in each country. The cataloguing of existing research outcomes into a global dataset will provide confidence in application of models such as iRAP and IHSDM. Key elements could include:
- Thorough review of existing research knowledge of countermeasures used in LMICs.
- Case studies of LMIC specific countermeasures - e.g. rock gabions as a road barrier.
- Influence of multiple countermeasures on crash reduction at a single site and the appropriate estimation of aggregated benefits (e.g. validation of the recent ARRB research that suggest "x 0.6 reduction" on individual summed benefits for the overall benefits of packages of multiple countermeasures).
- The specification of "Safe System compliant" countermeasures that can reduce almost 100 per cent of deaths and severe injuries, versus "supporting". countermeasures that are effective but have a supporting role in only partially reducing likelihood or severity.
- Review of the specification, costing and treatment life of countermeasures and how they differ from country to country.
- Road width/sealed shoulders and the influence on risk to car occupants and pedestrians based on actual usage patterns of the shoulders (e.g. an inside overtaking lane, additional traffic lane).
- Influence of low labour costs and high material costs on selection of countermeasures (particularly imported equipment) and options for innovative alternatives.
Detailed investigation of rear end crash types and potential solutions
Many developed countries are reporting an increase in rear end related fatalities and serious injuries as higher volumes and higher speed infrastructure such as freeways become common. The research would focus on:
- The scale of fatalities and serious injuries that are a result of rear-end crashes.
- Factors influencing rear-end crashes and the effectiveness of infrastructure/ITS countermeasures that may reduce them.
- Development and inclusion of a "Rear End Road Protection Score" model in the iRAP star rating protocol and associated countermeasures in the iRAP Safer Roads Investment Plan.
Speed and crash risk
The critical impact of speed on safety is well understood. The safety of infrastructure cannot be understood without an appreciation of vehicle speeds and road use at the location. The research package would investigate the following issues:
- Quantitative research to investigate the wide anecdotal discussion and acknowledgement that road rehabilitation in LMICs increases operating speed, with an associated impact on fatalities.
- More precise estimation of injury generation at low ends of the speed spectrum, in particular relation to vulnerable road users.
- The impact of the speed profile over a typical day (e.g. peak hour congestion speeds versus late night free speeds) and the associated fatality and serious injury crash risk as a function of volume.
- Detailed investigation of the impact of changes in speed on the likelihood of a crash and on the severity of a crash.
- Update of speed related risk factors and methodologies in the iRAP models as required.
Legislative barriers to improved road safety
In many countries, legislative barriers exist that impact the ability to implement countermeasures that are proven to be effective in other locations. Key issues to investigate include:
- Current design guidelines/standards/regulations in LMICs and their impact on the choice and availability of good and innovative design.
- Requirements for primary legislation for specific road features such as road humps and traffic calming measures that are otherwise legally a hazard positioned in the road.
Crash risk variability with traffic volume & mix
The relationship between crash risk and traffic volume is an essential element in the prediction of likely fatal and serious injury crash outcomes and therefore associated economic benefits of investment programmes. The relationship is expected to vary in relation to road cross-section, capacity of the road and other features. The research will consider the following:
- Relationship of fatal and serious crashes with traffic volumes and how they vary by time of day, crash type and road user type.
- Relationship of fatal and serious crashes with traffic volumes in relation to star ratings for various road users and associated road features such as cross section, volume/capacity ratio and speed.
- The relationship between side road traffic volumes and crashes and how they contribute to risk along the major roads they intersect.
- Improvement in the understanding of head-on crash risk on undivided roads in LMICs in particular relation to driver behaviour, overtaking demand and typical overtaking movements undertaken.
- Relationship of fatal and serious crashes with weather in relation to star ratings for various road users and the related impact on effective countermeasures (e.g. snow/ice specific treatments, treatments that cannot be used in certain weather conditions).
Key economic, social and health measures important for road safety investment decision making
The UN Decade of Action requires a quantum change in activity in relation to the five pillars identified in the UN Action Plan. This requires the appropriate demonstration of benefits and quantification of investment returns to ensure confident resource allocation by Government and the international community. The research will focus on:
- Identification of the key road safety performance indicators relevant to treasury, finance, health, social welfare, transport, road agency, insurance and business.
- Development of the preferred set of indicators relevant to road infrastructure investment and the impact they have across all sectors detailed above.
- Effective rules of thumb for estimating the individual and/or combined effect of the influence of changes in GDP, traffic, mode shift, countermeasure costs and behaviour change when estimating crash reduction benefits.
- Better description of total community value lost - including the relationship with DALYs and crash measures such as MAIS.
- Variation of DALYs or similar measures by road user type and age.
Road Safety Toolkit
The Road Safety Toolkit is a free resource that aims to provide simple, accessible information on best practice in relation to road safety engineering, road user safety and vehicle safety. The value of the tool will be increased with a greater number of case studies from individual countries around the world. The research will focus on:
- Sourcing of case studies from each region around the world and translation into relevant languages (e.g. 2+1 designs, traffic calming, pedestrian treatments).
- Development of a section on road safety management with links to "road safety strategies" from around the world.
Dr Steve Lawson, iRAP Technical Director,