Highways Agency

Chapter 6 - Conclusions and Recommendations

6.1 This chapter draws together the discussion and conclusions reached by the Group into a series of recommendations, many of which require further work to be undertaken or are suggestions for more study and research.

Conclusions

6.2 The Group has reviewed the current standard under the four headings that set the scope of its work in Paragraph 1.7 namely:

• Identify and consider UK research and studies related to the protection from hazards of errant vehicles leaving the nearside of major roads;

A comprehensive analysis of nearside single vehicle accidents on English roads has confirmed the importance of preventing errant vehicles from striking hazards along the edges of roads. Vehicle impacts with obstructions such as trees, posts, and telegraph poles are most likely to result in fatal or serious injury to the vehicle occupants and should have a high priority for protection by a safety barrier. Whilst there are a significant number of such accidents on the major road network, there is a more serious problem to address on the rest of the UK road network. Using accident data and recent UK research, the Group reviewed the performance of the current safety barrier standard. The Group found that the evidence demonstrates that safety barriers can themselves present a hazard to errant vehicles but the Group concluded strongly that, on the whole, the standard provides the right level of protection. They also found no overwhelming evidence to suggest that there is a significant problem with Heavy Goods Vehicles leaving major roads on the nearside, which lead the Group to conclude that there should be no general increase in the level of containment. The Group also supported the approach in the current standard where selected hazards are identified for protection, at an appropriate level of containment.

• Consider options for change by assessing quantifiable risks, costs and benefits, and the implications for non trunk roads;

The accident data was further analysed for the Group to estimate the likelihood of accidents occurring and to compare the effect of interacting with different hazards and the associated risks and consequences. The Group concluded from this that the current policy on protection strikes the right balance and that accidents involving vehicles leaving major roads and reaching railway lines are extremely infrequent events. They acknowledged, however, that such events could, in exceptional circumstances, have very serious consequences for the rail industry. The Group accepted that implicit in the current standard is an assessment of which hazards require protection and that this is a form of risk assessment. In addition, experienced and qualified highway designers use the standard as a minimum provision but evidence shows that the provision on major roads generally exceeds the minimum requirements. The Group concluded that there is no evidence to support a step change in the current policy for safety barrier provision on either major roads or minor roads. They accepted that highway authorities operate procedures that are as safe as is possible, however, the approach to safety in the rail industry is rightly different and this is not always sufficiently taken into account in current roads practice. The railway safety approach is risk based where a protocol of comprehensive risk assessments is adopted and used. The Group concluded that whilst the evidence suggests that road/rail incidents are extremely infrequent for major roads, a more formal and transparent framework for risk assessment and an agreed protocol, common to both rail and road authorities, could help to better manage these risks.

• Identify and consider the practice and standards for the provision of safety barriers in countries where circumstances are similar to the UK;

A number of standards relating to safety barrier practices were collected from other countries. Within the time available it was not possible for the Group to study the effectiveness of these standards, or the result of applying the various standards to UK major roads. In general, the Group concluded that the current UK standard compares well with those from other countries where a minimum standard is specified. It was recognised that most of the international standards are aimed primarily at new road building and time did not allow the Group to determine to what extent these practices are applied retrospectively to the existing road networks. The Group concluded that there might be an advantage in understanding some other countries' practices and methods to determine whether they could be beneficial to the UK in determining the extent and location of safety barriers and also in adopting a more analytical risk assessment approach. Any such approach would require more comprehensive advice to be provided and for it to be better explained in the standard. The Group recognised that there is currently a lack of advice on risk assessment procedures and concluded that this should be provided.

• Consider the cost and practicality of implementation on new and existing roads.

Chapter 5 of the Report contains the results of the Group's consideration of costs for installing a limited additional length of safety barrier where this could be justified, following a detailed risk assessment. The Group concluded that there is no evidence to support a general increase in protection measures on the UK's major roads, but that there is a lack of advice for local authorities to use on minor roads. They acknowledged that the analysis of English accident data shows that the risks to vehicle occupants in accidents involving many unprotected roadside hazards are greater than those from a vehicle reaching a railway line. The Group concluded that the unit cost of additional lengths of safety barrier is small for new works but is considerably greater for existing sites, which would require traffic management. However, they also concluded that the overall costs of any changes in provision would be likely to be reasonably low.

6.3 The overriding conclusions from the Group are:

• The analysis of the accident data suggests that there are no serious shortcomings in the safety barrier standard and its application to the nearside of major roads.
• The current advice to road designers would benefit from a more detailed explanation of the derivation of the advice.
• There is a lack of advice for minor roads on the provision of safety barriers and this should be provided.
• There is a lack of advice on risk assessment for the provision of safety barriers and this, together with a management protocol for road and rail interfaces, should be provided.
• Current research targeted at UK roads has proved valuable in developing standards but more complete accident data and better feedback on barrier effectiveness and performance should be sought.
• The risk of a serious accident arising from a vehicle leaving a major road and reaching a rail line is extremely low but in exceptional circumstances can have serious consequences.
• Analysis shows that the risks to vehicle occupants in accidents involving many unprotected roadside hazards are greater than those from an errant vehicle reaching a rail line.
• International experience points towards some areas where more analysis and research is needed before changes to advice should be considered.

Recommendations

6.4 The Group having considered the conclusions make the following recommendations, grouped similarly to their conclusions.

6.5 The current standard has been shown to have the right balance for major roads and to cover the appropriate topics. The analysis of accident data has shown that priorities for protection of road users from nearside hazards are appropriate. The standard compares well with those from other countries in most respects but the form of any review and background to the advice is not clear. The Group recommends that:

1. The latest UK research and best practice from international experience is incorporated at the earliest opportunity into standards. (see paragraphs 2.20 and 4.7 - 4.22)
2. Additional research is targeted at issues where either accident data or international experience identifies potential shortcomings. In particular, research should be undertaken into understanding more about how and where errant vehicles travel after leaving the carriageway. (see paragraphs 2.20, 2.21 - 2.33 and 4.7 - 4.22)
3. The Highways Agency introduces a clearer and more open procedure for updating the standard relating to safety barriers. (see paragraphs 2.6, 2.7 and 2.18)

6.6 Accidents involving nearside hazards are a greater problem on minor roads where there is little advice available. The Group recommends that:

4. DTLR take the lead in bringing together the interested parties to prepare advice on appropriate mitigation measures for application on minor roads crossing rail lines. (see paragraphs 2.4, 2.29 and 3.11)

6.7 There is a lack of advice on risk assessment and there is a lack of clarity on where the responsibility lies between road and rail authorities for preventing errant vehicles accessing railway lines. It is clear that this must be overcome in partnership between the interested parties. The Group recommends that:

5. Risk assessments be further developed for the provision of safety barriers, including additional and/or alternative protection or mitigation measures to take account of local circumstances. (see paragraph 3.8)
6. A common risk assessment framework for road/rail interfaces be prepared and used in order to identify high risk sites and prioritise work programmes. (see paragraphs 3.9, 3.10 and 3.11)
7. The risk assessment methodology recognise the needs of both road and rail as separate authorities and their need to address wider safety interests. (see paragraph 3.10)

6.8 During the work of the Group it was found that the quality of accident data and the under-reporting of accidents needed to be addressed. Due to the lack of time the Group were unable to fully investigate the level of application of international standards and the relevant safety records. The Group recommends that:

8. The Highways Agency enhance the collection of accident data including reporting links matching barrier repairs with non injury accidents. Other national highway authorities are recommended to consider similar action. (see paragraphs 2.13, 2.14, 2.16, 2.22 and 2.23)
9. Data are collected on the implementation and effectiveness of barriers abroad. (see paragraph 4.5)

6.9 The Group has concluded that for major roads the analysis of the accident data suggests that there are no major shortcomings in the safety barrier standard or its application. As such, the data does not support the wider use of safety barriers everywhere on the road network. Further consideration and specific advice is required at certain locations, such as at road bridges over railways, where there could be exceptional, disproportionate consequences. The Group recommends that:

10. The standard is reviewed to take account of the Group's recommendations and the thinking behind the standard made clearer. (see paragraph 2.3 and 2.18)
11. Additional measures that may be required from application of the amended standard be implemented and should apply to works on the existing road network as well as to new works. (see paragraph 5.5)

6.10 The Group recommends that:

12. Action to implement the recommendations is undertaken within twelve months and the Highways Agency report on progress at that time.