Road Safety Manual
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on implementing safe system infrastructure

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9.3 Policies, Standards and Guidelines

Development of Policies, Standards and Guidelines

Roles, Responsibilities, Policy Development and Programmes provides direction on the development of policies for road safety outcomes. This includes the need to understand current road safety problems through the analysis of data; and the development of a road safety plan that includes appropriate targets and interventions. The development of infrastructure policy follows the same process, and should be considered as part of broader road safety policy development.

GRSF (2009) provides advice for countries that are establishing road safety capacity (i.e. LMICs) in terms of their investment strategies (also see The Road Safety Management System), and this advice is useful for development of policies, standards and guidelines. The advice suggests that the initial focus for such countries should be targeted on high crash density demonstration corridors and urban areas. The value of this demonstration corridor approach has been discussed throughout this manual, including the case study from Belize in Box 2.

GRSF (2009) also discussed the need to review and benchmark safety policies and interventions with other countries, and that this should lead to the commencement and implementation of reforms. This advice is equally relevant to road agencies attempting to implement new infrastructure policies. In order to focus attention to the highest priority areas, and to build capacity through doing, policies to address crashes at these locations can be addressed as a priority. Similarly, awareness of successful approaches adopted in other countries, and movement towards such approaches is a valuable method.

Little guidance exists on the mechanisms for transforming road infrastructure safety policy into relevant standards and guidelines. Rather, there are a number of examples that highlight what can be achieved. Many countries have developed their own standards and guidelines, and in some cases these may be adopted for use in other countries (although as noted elsewhere, caution should be used where the context is different). Croft et al. (2010) provide some advice based on the development of national guidelines in Australia. Some of the key elements from this process were that these were produced:

  • under the direction of a review panel or task force;
  • based on review of existing guidelines and related technical documents ;
  • so as to incorporate new strategic directions (e.g. the Safe System design principles);
  • to include relevant research results, technological developments and practitioner experience.

There is a need to constantly review standards, policies and guidelines, and to improve these based on recent innovations. An evidence-based approach is required to ensure that expected safety benefits from any changes are attained. Benchmarking of approaches used in countries that perform well in safety is a good step to helping identify possible innovations. Further analysis may be required to ensure that changes will have a positive safety benefit when applied in a different country. Demonstration projects to trial new innovations are useful to establish whether such changes are beneficial in a controlled environment. Once evaluated and shown as successful these can be applied more broadly, and recommended changes reflected in appropriate guidance documents.

Examples of Infrastructure Policies, Standards and Guidelines

There is no set template for the development of policies, standards and guidelines, and those countries that do have comprehensive coverage of these vary in content, often reflecting local conditions. For those who wish to develop or improve policies, standards and guidelines it is beneficial to benchmark against good performers and draw upon international and regional examples of good practice. The sections below outline examples at global, regional and country levels, and may serve as a starting point in this exercise.

Global level

There has been a significant shift in road safety policy in recent years in response to the Safe System approach. This issue, including the origin of the approach and its implications, are discussed in detail in The Safe System Approach. The Decade of Action for Road Safety, described in Key Developments in Road Safety, has also resulted in some significant policy shift. At the international level, the UN Road Safety Collaboration (UNRSC) has developed a Global Plan that includes policy guidance on safe roads and mobility (also see The UN Decade of action and global plan). The plan states that the purpose of this pillar is to:

Raise the inherent safety and protective quality of road networks for the benefit of all road users, especially the most vulnerable (e.g. pedestrians, bicyclists and motorcyclists). This will be achieved through the implementation of road infrastructure assessment and improved safety-conscious planning, design, construction and operation of roads.

Source: UNRSC, 2010, p.12.

The plan suggests that this can be achieved by six key activities, namely to:

  • promote road safety ownership and accountability among road authorities, road engineers and urban planners;
  • promote the needs of all road users as part of sustainable urban planning, transport demand management, and land use management;
  • promote safe operation, maintenance and improvement of existing road infrastructure ;
  • promote the development of safe new infrastructure that meets the mobility and access needs of all users;
  • encourage capacity building and knowledge transfer in safe infrastructure;
  • encourage research and development in safer roads and mobility.

Details on how each of these activities might be delivered can be found in Box 9.5. Individual countries will need to assess how they respond on each of these activities, but the information provides a useful checklist of actions that can be undertaken to improve the management and delivery of safe roads.

Box 9.5: Pillar 2 of the Global Plan: Safer roads and mobility

Activity 1 Promote road safety ownership and accountability among road authorities, road engineers and urban planners by:
  • encouraging governments and road authorities to set a target to eliminate high risk roads by 2020;
  • encouraging road authorities to commit a minimum of 10% of road budgets to dedicated safer road infrastructure programmes;
  • making road authorities legally responsible for improving road safety on their networks through cost-effective measures and for reporting annually on the safety situation, trends and remedial work undertaken;
  • establishing a specialist road safety or traffic unit to monitor and improve the safety of the road network;
  • promoting the Safe System approach and the role of self-explaining and forgiving road infrastructure;
  • adhere to and/or fully implement the regional road infrastructure agreements developed under the auspices of the United Nations regional commissions and encourage the creation of similar regional instruments, as required;
  • monitoring the safety performance of investments in road infrastructure by national road authorities, development banks and other agencies.

Activity 2 Promoting the needs of all road users as part of sustainable urban planning, transport demand management and land-use management by:

  • planning land use to respond to the safe mobility needs of all, including travel demand management, access needs, market requirements, geographic and demographic conditions;
  • including safety impact assessments as part of all planning and development decisions;
  • putting effective access and development control procedures in place to prevent unsafe developments.

Activity 3 Promote safe operation, maintenance and improvement of existing road infrastructure by requiring road authorities to:

  • identify the number and location of deaths and injuries by road user type, and the key infrastructure factors that influence risk for each user group;
  • identify hazardous road locations or sections where excessive numbers or severity of crashes occur and take corrective measures accordingly;
  • conduct safety assessments of existing road infrastructure and implement proven engineering treatments to improve safety performance;
  • take a leadership role in relation to speed management and speed sensitive design and operation of the road network;
  • ensure work zone safety.

Activity 4 Promote the development of safe new infrastructure that meets the mobility and access needs of all users by encouraging relevant authorities to:

  • take into consideration all modes of transport when building new infrastructure;
  • set minimum safety ratings for new designs and road investments that ensure the safety needs of all road users are included in the specification of new projects;
  • use independent road safety impact assessment and safety audit findings in the planning, design, construction, operation and maintenance of new road projects, and ensure the audit recommendations are implemented.

Activity 5 Encourage capacity building and knowledge transfer in safe infrastructure by:

  • creating partnerships with development banks, national authorities, civil society, education providers and the private sector to ensure safe infrastructure design principles are well understood and applied;
  • promoting road safety training and education in low-cost safety engineering, safety auditing and road assessment;
  • developing and promoting standards for safe road design and operation that recognize and integrate with human factors and vehicle design.

Activity 6 Encourage research and development in safer roads and mobility by:

  • completing and sharing research on the business case for safer road infrastructure and the investment levels needed to meet the Decade of Action targets;
  • promoting research and development into infrastructure safety improvements for road networks in low-income and middle-income countries;
  • promoting demonstration projects to evaluate safety improvement innovations, especially for vulnerable road users.

 

© ARRB Group

Still at the global level, the UNRSC (2010) in their Safe Roads for Development document highlight some priority infrastructure policies, particularly in relation to LMICs. They suggest that priority crash types be targeted on high risk roads. Crash types include those involving vulnerable road users walking or cycling across or along the road; head-on crashes; side impacts at intersections; and run-off-road crashes. High risk roads refer to the small proportion of the world’s roads where the majority of fatal and serious injury crashes occur. They highlight that in the UK, just 10% of roads account for more than half of all road deaths, and around a third of all serious injuries. They also suggest that in Bangladesh, 3% of the arterial road network accounts for 40% of road deaths.

The priority actions for these roads and crash types include that:

  • cities and communities should be planned for the growing number of people who do not own a car (i.e. vulnerable road users);
  • planning and provision for vulnerable road users should include:
  • land use control;
  • widening and repair of footpaths;
  • enforcing laws to prevent vehicles from parking on footpaths;
  • removing barriers and street furniture on footpaths;
  • improvements to pedestrian crossings;
  • influencing land use planning alongside major roads (i.e. linear development).

Linked to this international policy context, a number of global guidelines have been produced to help address road safety. Produced by the World Health Organisation (WHO), Global Road Safety Partnership (GRSP), FIA Foundation and the World Bank, guidelines exist on various elements linked to road safety infrastructure. Of greatest interest to the audience of this manual are the guidelines on data systems (as discussed in Effective Management And Use Of Safety Data), and speed management and pedestrian safety. Other global guidelines exist on helmets, seatbelts, child restraints, and drinking and driving. All of the guidelines can be downloaded from the WHO website (http://www.who.int/roadsafety/publications/en/).

PIARC (2012) conducted an important review of national road safety policies and plans. This addressed policies for infrastructure improvements, and included the following key conclusions:

  • A better understanding is required regarding the linkage between infrastructure and speed.
  • A mixture of ‘spot location’ and system-wide approaches are used in different countries (and within countries). There is a place for both approaches, but there needs to be recognition that the current system is generally not safe.
  • Risk assessment processes (Road Assessment Programmes are specifically identified) are highly beneficial, not only in identifying risk locations (including when crash data is not adequate), but also in identifying treatments. The process is also useful to help raise awareness about road features that contribute to risk, and how some treatments can be more effective than others.
  • There is a need to conduct network-wide assessments, and prioritise action based on potential benefits.
  • Comparing crash rates to an average for the network might not result in substantial safety investments, as this approach will generally maintain the average.

This current document is obviously the key guidance document produced by PIARC on road safety infrastructure. In addition, there are many other important documents relevant to road safety policy and guidance that can be accessed from the PIARC website (http://www.piarc.org/en/knowledge-base/road-safety/publications-safety/). These cover design and development of road infrastructure, road safety audits, safety on construction zones, vulnerable road users, road operation, road safety in winter conditions, road tunnels and others. The documents include those listed in Box 9.6

Box 9.6: PIARC road safety publications (2008-2013)

Road accident investigation guidelines for road engineers (2013 – 2013R07EN)

Comparison of national road safety policies and plans (2012 – 2012R31EN)

Road safety inspection guidelines for safety checks of existing roads (2012 – 2012R27EN)

Human factors in road design. Review of design standards in nine countries (2012 – 2012R36EN)

State of the practice for cost-effectiveness analysis, cost-benefit analysis and resource allocation (2012 – 2012R24EN)

Best practices for road safety campaigns (2012 – 2012R28EN)

Taking advantage of intelligent transport systems to improve road safety (2011 – 2011R03EN)

Road safety audit guidelines for safety checks of new road projects (2011 – 2011R01EN)

PIARC catalogue of design safety problems and potential countermeasures (2009 – 2009R07EN)

Tools for road tunnel safety management (2009 – 2009R08EN)

Human factors guidelines for safer road infrastructure (2008 – 2008R18EN)

Human factors and road tunnel safety regarding users (2008 – 2008R17EN)

 

As well as supporting the UNRSC in the development of the Global Plan, the World Bank Global Road Safety Facility has produced a number of policy and guidance documents, many aimed specifically for use in LMICs. Comprehensive resources to assist in the delivery of safe road infrastructure can be found on the Facility’s website (http://go.worldbank.org/9QZJ0GF1E0).

Regional level

Regional policy for the delivery of safe infrastructure can also be found, most notably in the EU Directive 2008/96/EC. Issued in November 2008, this directive covers the trans-European road network, although it is suggested that the provisions of the Directive can be applied to the national road network. Separate European guidance on the secondary road network can also be found (see e.g. Polidori et al., 2012).

Provisions of the Directive include that:

  • road safety impact assessment be carried out on all infrastructure projects on the trans European network. These are designed to assess the impact on safety of different planning alternatives;
  • road safety audit be conducted on all infrastructure projects. Such audits should be conducted at the draft design, detailed design, pre-opening and early operation stages;
  • safety ranking be undertaken in order to identify roads with a higher than average crash risk ;
  • data systems be put in place to collect information on fatal crashes, and calculate the average social costs of fatal and serious injury crashes.

The Directive also highlights the need to adopt guidelines to support these activities, and provides content on appropriate training, exchange of best practice and continuous improvement. A recent review of the Directive (European Commission, 2014) indicated that more systematic processes had been put in place in EU countries to safely manage infrastructure as a result of the Directive.

Further details on the approaches highlighted above can be found in Assessing Potential Risks And Identifying Issues.

Regional approaches to road safety in LMICs have also been developed, often under the Development Bank, UN Regional Commission, or regional economic grouping leadership. As an example, the Asian Development Bank (ADB) has developed a Sustainable Transport Initiative that directly addresses road safety through a Road Safety Action Plan for the region (www.adb.org/documents/road-safety-action-plan). This discusses the mainstreaming of road safety within areas of ADB operations. An ADB Road Safety Group has been established, and one of the objectives of this group is to make available key reference documents, terms of reference, guidance, and tools for use by those in the region. The summary document ‘Improving Road Safety in Asia and the Pacific’ provides useful advice and reference material on road safety based on recent ADB experience (see http://www.adb.org/sites/default/files/evaluation-document/36104/files/road-safety.pdf).

Box 2.4 in Key Developments in Road Safety describes the regional approach that was taken in the development of the African Road Safety Action Plan (2011–20). The development of this plan involved a wide range of stakeholders. At the country level, different approaches have been taken to the development of policy, and provision of relevant infrastructure standards and guidelines. This is often in response to different local context, including different legislation or safety issues. As identified elsewhere in this manual, there is typically no one correct approach to successfully managing road safety. However, there are often general principles that are universal.

Country level

In the United States, the Highway Safety Manual (AASHTO, 2010) provides detailed guidance on the roadway safety management process. The approach proposed is broadly aligned with that used in many countries, and it is no coincidence that the approach mirrors the structure of Planning, Design and Operation of this manual, particularly Assessing Potential Risks And Identifying Issues to Monitoring and Evaluation of Road Safety. The process includes keys steps, from network screening (identifying and ranking sites) to safety effectiveness evaluation (monitoring effectiveness).

Pre-dating the Highway Safety Manual, AASHTO produced a series of guides to assist in the delivery of the Strategic Highway Safety Plan. This comprehensive suite of 20 guides provides direction on key strategic issues. Those relating to road infrastructure include: guides on addressing collisions with trees in hazardous locations, head-on collisions, unsignalised and signalised intersections, run-off-road collisions, collisions on horizontal curves, utility poles, pedestrians and work zones. These documents can be downloaded from the Highway Safety Plan website (http://safety.transportation.org/guides.aspx).

Other countries have a similar set of guidelines to advise on effective road safety infrastructure management. For example, the Austroads Guide to Road Safety (currently in nine parts) provides guidance for Australia and New Zealand (see www.austroads.com.au); the Dutch have the Road Safety Manual (CROW, 2009) and Advancing Sustainable Safety (Wegman & Aarts, 2006); and the UK has the Good Practice Guide (DTLR, 2001). These documents are accompanied by many other relevant standards and guidelines in each country. As an example, Certu, the Centre for the study of urban planning, transport and public facilities in Lyon, France has produced a number of guides and reference documents (some of which have been translated into English; see http://www.territoires-ville.cerema.fr/). Also from France is the Transportation Safety in Urban Area: Methodological guide (Certu, 2008; available in French and English).

Although all of these documents are technically sound and serve as a useful basis for infrastructure safety management, as identified above, care should be taken when translating these guidelines to other countries. Different approaches, and particularly different solutions, may be more appropriate when the context (including traffic mix) is different.

As already identified in this section, different policies or guidance are sometimes issued for roads of different function. The EU Directive only refers to the trans-European road network, while additional information is available for lower order roads (see e.g. Polidori et al., 2012 for guidance on the secondary road network). Although the general principles that apply to each type of road are the same, often the detail can be different. Similarly, some countries issue guidance for local roads, recognising that the constraints can be different. Examples include The Good Practice Guide from the UK (DTLR, 2001); FHWA guidance in the United States on Developing Safety Plans: A Manual for Local Rural Road Owners (Ceifetz et al., 2012); and the Local Government and Community Road Safety guide (Austroads 2009; also see Austroads 2010a). McTiernan et al. (2010) also provide useful guidance on development of the Safe System approach for local government in Australia. However, usually only one guidance document exists covering road safety management of all roads, with those managing different parts of the network expected to adapt the information to their own circumstances.

 

Road Design and Traffic Management Guidelines

Along with guidance documents targeted at safety-related topics (discussed in Examples of Infrastructure Policies, Standards and Guidelines in Policies, Standarts and Guidelines and Intervention Selection And Prioritisation) many countries have comprehensive guidance on the design, construction, traffic management and maintenance of roads. These typically embed safety, although it is noticeable that many have not yet fully embedded Safe System principles. Guidelines are often slow to include innovative approaches to road design, as these may take a number of years to construct and evaluate; there may be infrequent updates of guidelines; and there may be reluctance to change established practice. An evidence-based approach is required, as well as a process to facilitate continual improvement and updates to guides.

It is not possible to include comprehensive advice in this document on issues relating to road design, traffic management and maintenance, but rather readers are directed to appropriate country-based guidelines for this detail. As for safety-related guidance, countries are encouraged to benchmark against good performers (i.e. those with low crash rates) when developing or updating their own guidance.

Road design and construction involves the geometric design, and structural design of the roadway. A key objective of geometric road design is to optimise operational safety and transport efficiency within constraints (including budgets, environmental concerns and other social outcomes). Design needs to take into account the traffic volume and type of traffic expected to use the road. The elements that are typically thought to impact on efficiency and safety include intersections, horizontal curves, vertical curves and gradients, cross-section (lane and shoulder width, medians and roadsides), and merge/diverge areas, and design guides typically cover these issues in detail. Information is available on the influence of different design elements and the impact this has on safety outcomes (e.g. AASHTO, 2010; Harwood et al. 2014; Austroads 2010b).

The following points provide a brief description of effective countermeasures and the safety benefits of different design elements based on the above references. It is important to note, however, that although these treatments have a known effectiveness in reducing crash risk in HICs, it may be a different case for LMICs. For example, wider sealed shoulders may provide additional space for drivers to recover after a driving error, but in LMICs this area may be utilised by the community to set up a roadside stall.

Design criteria include:

  • Design speed: The selected design speed influences the characteristics of various geometric elements on a roadway, such as lane widths, horizontal and vertical curves, and sight distance. The speed selected should reflect the speed drivers expect to travel at on a section of roadway, and should take into account the abutting developments, the roadway function and its physical limitations (due to terrain, expected traffic volumes, etc.).
  • Lanes and shoulders: Crash risk can be linked to the total seal width (lane and shoulder seals). Crash risk decreases with increasing seal width (i.e. wider lanes and larger shoulders), as the sealed area provides a recovery zone for errant vehicles and space for evasive manoeuvres. For two-lane rural roads, shoulder sealing can reduce crash risk by up to 35%.
  • Horizontal alignment: This involves the design of horizontal curves along a road. Crash risk increases with decreasing curve radius (i.e. as a turn gets tighter). The risk increases more rapidly for curve radii below 400m. The crash risk is also higher for isolated curves (or where the driver might not be expecting it), and lower for curves in a sequence of similar-standard curves.
  • Vertical alignment: This involves the road grade (the rate of change of vertical elevation) and vertical curves (i.e. crests and sags). Sag curves are not known to have any significant effect on safety. The most crucial effect crests have on safety is through sight distance, which is covered in the next bullet point. There is a small relationship between crash risk and vertical grade – the crash risk also increases more rapidly for grades beyond 6% as vehicle speeds becomes more difficult to manage.
  • Stopping sight distance: This is the distance required for a driver to recognise a need to stop and brake to a stop from a particular speed. Horizontal and vertical curves limit a driver’s sight distance, particularly crests. There is the suggestion of a small increase in crash risk as sight distance over a crest decreases. This risk increases more rapidly for sight distances below 100m. Road widening (either as wider shoulders or an overtaking lane) over a crest with less than adequate sight distance can be an effective countermeasure rather than flattening the crest. It is suggested that safety is unlikely to be affected by limited stopping sight distance; however improving limited sight distance at locations where other vehicles may be slowing or stopping (in particular intersection sight distance) can be extremely important for safety.
  • Roadside clearance: Also known as horizontal clearance or lateral offset, roadside clearance is distance between the edge of the roadway or shoulder to a vertical roadside obstruction, and the type of obstruction a vehicle might hit. Crash risk can potentially be reduced by 35 to 45% when all roadside hazards are removed (e.g. trees, poles, fences, etc.); however a barrier installation can be an effective countermeasure for reducing run-off-road crashes. It should be noted that a ‘clear’ roadside must also be flat or mildly sloping (e.g. 1:4 or flatter), and that roadsides with steeper gradients can have a large impact on vehicle safety.

The following references provide examples of road design guidelines from different countries:

Traffic management concerns the safe and efficient movement of people and goods. This includes provision for pedestrians, cyclists and other vulnerable road users. Again, many guidelines exist to assist in management of roads and traffic, and these typically relate closely to design principles, the capabilities of road users, and to vehicle characteristics. Guidelines typically cover aspects such as traffic theory, traffic studies and analysis, and the use of traffic control devices (signs, line markings) and other associated measures (traffic signal operation and street lighting). They may also cover issues such as speed management and traffic calming, public transport facilities, parking and management at roadworks.

Example guidelines include:

Typically design guidelines are prepared with an underlying assumption that they will be used where there are minimal constraints in delivering the project. These are sometimes referred to as ‘greenfields’ sites and the Normal Design Domain (NDD) design criteria should be used. However, it is far more common to make safety or other improvements at locations where constraints do exist, such as upgrades to existing roads, or ‘brownfields’ sites. Constraints can include things like an existing road alignment, utilities (including poles), drainage, access points, etc. In these situations, applying NDD values can make projects financially unviable. In addition, there may be cultural, heritage or environmental issues that limit application of NDD standards.

Many jurisdictions have developed procedures for dealing with departures from the NDD. When deviating from recommended design criteria, an exception report is required. This should be produced early in the design stage, and it should include clear and careful consideration of the safety impacts of any departure, as well as the impact on traffic operations. Mitigating strategies to minimise any adverse risk from the exception should also be provided.

Guidance on safety impacts resulting from departures in the NDD can be found in several countries, along with information on mitigation strategies. Useful examples include guidance by the New Jersey Department of Transportation (2012); the Queensland Department of Transport and Main Roads (2013) and Stein and Nueman (2007).

One recent approach from the United States (but also applied in other locations using different names) is the concept of ‘performance-based practical design’ (PBPD), which has evolved from the ‘practical design’ approach. This involves designing projects to stay within identified needs, and removing non-essential elements. This has the effect of lowering costs, and enabling improvements at a greater number of locations. The move to a ‘performance-based’ approach means that informed decisions will be made using analysis tools (for example, the Highway Safety Manual). Agencies using PBPD would have specific, long- and short-term, performance goals that may apply to a project, a whole corridor, or the overall system. Using available performance-analysis tools and qualitative assessments, projects would only include those features that serve those long- and short-term performance goals. Projects would not need to include features that provide performance exceeding the stated goals, fail to serve those performance goals, or are inconsistent with the purpose and need. This removes a concern relating to Practical Design that agencies may overemphasize short-term cost savings without a clear understanding of how such decisions would impact other objectives (such as safety and operational performance, context sensitivity, life-cycle costs, long-range corridor goals, liveability, and sustainability).

PBPD is a philosophy of balancing project purpose and need, design standards, life-cycle costs, operational and safety performance and sustainability. To gain the greatest benefit from PBPD, it is highly encouraged to take a system-wide perspective and incorporate PBPD concepts in all decisions related to planning, programming and project development. Starting at the planning and programing phase, a multi-disciplinary group can weigh the options and trade-offs to define performance goals and a focused project purpose and need that is used throughout the life of the project.

Reference sources

No reference sources found.