Road Restraints Risk Assessment Process (RRRAP)

(updated 25th March 2020)

*** Special notice: Coronavirus – Home broadband usage and RRRAP operation. ***

Currently the RRRAP system is operating well within the resources allocated to it and therefore any access or speed related issues are likely to be related to the extraordinary daytime usage of broadband from home users with the demand for intensive bandwidth dependent applications such as video streaming services or gaming. Should users experience issues with the performance of RRRAP, it is likely to be as a result of local strain on broadband services.

If you are in the hazard definition phase of RRRAP, populating data, this is a low intensity data demand activity and where possible other access points such as different broadband suppliers could be attempted, i.e. a different service provider Virgin / BT derived supplier if available to you (neighbour), a works mobile data stream or if rate inclusive, a personal mobile data package connection.

The intensive data requirement for RRRAP is the initial ‘calculate risk’ processing whereby all hazards are ‘number crunched’ together. After that initial processing, only individual changes are processed although some changes which are applicable to multiple hazards will have wider impact, changes to Basic details (AADT, Vehicle percentages) or collective hazard entries ( Hardstrip or Hardshoulder widths, verge details etc).

If difficulties are experienced, continuing to work on other aspects of the design and calculating risk at times of quieter demand may be appropriate (the calculate risk operation takes between 45 seconds and two minutes). Times such as non-core hours but also breakfast, lunch or dinner times where usage may decline temporarily.

It is hoped difficulties remain at a level that is manageable but should any occur, further advice will be issued to address any such reported issues.


From Sunday 1st September 2019, ALL NEW SCHEMES on the UK high speed Trunk Road Network which comply with the implementation requirements of TD19/06 are required to be undertaken on RRRAP v3 which is hosted on the cloud (account application process below). The UK Trunk Road network consists of roads operated by Highways England and designated Roads operated in the devolved administrations of Scotland, Wales and Northern Ireland.

The Risk based Road Restraint Systems Standard does not follow the traditional standard format.  The Standard has two parts that must be used together,

The RRRAP provides the designer with a tool to assist in the provision of a safe road design for hazards that are sited adjacent to the carriageway. v3.0 is a cloud hosted tool.

The RRRAP tool provides the client an auditable record of the roadside in the form of a list of roadside furniture, structures, water hazards, roads, railways and other features which pose a hazard to errant vehicles that have left the carriageway. It also provides a record of the solution the designer has optimised through the process of hazard design, moving or removing hazards, specifying setback – working width combinations and benefit cost analysis for installation specification and future maintenance.

It applies site specific data to each hazard allowing the risk of impact and likelihood of occupant injury to be assessed for any hazard with multiple complex factors being applied which may influence the risk of life changing injury. Factors such as offset from the running lane, topography of the ground in advance of the hazard, the aggressiveness of the hazard itself and other factors such as bend severity, accident history, traffic volume, vehicle type balance and any effects on third parties.

The formulae within the RRRAP reproduce research findings reflect risk factors found in a number of research reports undertaken in the UK and Worldwide. These are summarised in the Errant Vehicle report also stored on this site. The outputs of RRRAP were benchmarked against IRRS and TD19/85 and have been developed through the continuous improvement process over the last 15 years. The RRRAP outputs provide a good basis for hazard mitigation solutions whether that is removal of the hazard, installation of passively safe furniture or protection with vehicle restraint safety systems. The provision of solutions meeting or exceeding current standards are subject to agreement with the client and the provision of solutions not meeting current standards require agreement with the overseeing organisation through the departure from standards process.


Each organisation will request a user name and password for their organisation by means of a nominated super-user who will administer access to their allocation of record slots to other designers within their organisation. All slots / records are accessible ONLY to the organisation to which they are allocated.

Super-users will be notified of their account details by email together with the location of the login page.

The organisation's super-user will need to demonstrate current and future scheme records or justify the issue of an account for other reasons (education, training or research purposes).

The number of slots allocated to each organisation will be made based on workload / expected users.

PLEASE NOTE: RRRAP is not a storage system, records should be downloaded / backed up on a frequent basis. It is required that once the design has reached the print off appendix 4-1 stage, the record is removed (or downloaded by csv file) to free up record slots.


Send email request


The email shall contain the following details : -

RRRAP Introduction Videos

For Super-users.

For Users.

Written User Guide (in-tool guidance is updated frequently)

(PDF, Opens new window) RRRAP v3.0 Desk guide

Advice on the use of TD 19/06 in Northern Ireland

In Northern Ireland TD 19/06 and the RRRAP was implemented from 1st August 2007. For further information please contact the Engineering Policy Branch, Tel. 028 90540405.

Advice for Low Flow Trunk Roads in Wales and Scotland

The RRRAP allocates an aggressiveness value to each hazard adjacent to the road and quantifies risk by estimating the equivalent fatalities per vehicle km. For very aggressive objects adjacent to high speed roads, the RRRAP indicates that the provision of a Vehicle Restraint System (VRS) is required to lower the risk to an acceptable level, regardless of the traffic flow.

However, as traffic flow decreases the benefit/cost ratio of solutions also decreases. This is because although the overall risk decreases when a VRS is provided, the benefit is relatively small due to the relatively low number of accidents it prevents. Therefore, where two-way traffic flows are less than 5,000 AADT the designer should; assess whether the output from the RRRAP are practicable, if the benefit/cost ratio results warrant VRS provision  and discuss their findings with the Overseeing Organisation.

This does not apply to the provision of parapets.

RRRAP v1.3a 2016 in excel format (discontinued for the high speed trunk road from September 1st 2019 except Temporary Barrier assessment for hazards within roadworks exceeding 28 days).

RRRAP v1.3a will continue to be available for high speeds roads which are not UK trunk roads and for Temporary Barrier provision to protect vulnerable or hazardous features adjacent to live lane traffic.

RRRAP v1.3a excel spreadsheet tool.

RRRAP spreadsheet user guide

If you have any questions or problems with the RRRAP then please consult the RRRAP problem check sheet for commonly encountered problems before contacting us.

This worked example is a spreadsheet with basic details already filled out such that it is validated as functional in being able to calculate those entries already populated. It can be used to verify IT system issues or examine problems with incorrect data entry by the user.