Road Safety Engineering

Cost Effective Local Safety Schemes

Introduction

The number of road traffic casualties continues to be unacceptably high. The municipal engineer has an important role to play in providing a ‘safer’ infrastructure for all road users.

Road Accident Statistics (GB 2006)¹

Fatal Injuries	3,172
Severe Injuries	28,673
Slight Injuries	226,559
All Casualties	258,404

Compared with the average number of casualties between 1994 and 1998, fatalities have decreased by 11%, serious injuries by 35% and slight injuries have increased by 17%. Overall, casualties have decreased by 19%, while in the same period the distance travelled by all vehicles on the UK's roads increased by 15%.

However, this still equates to approximately 9 fatalities and 80 personal injuries each day. The level of human suffering caused is immense and engineers are well placed to help reduce the numbers of accidents, casualties and the impact on society.

In addition to this, the under-reporting of casualty statistics obtained from Police (STATS 19) data has been acknowledged for many years. Whilst fatalities are almost certainly accurate; it is estimated that there are around three times more seriously injured casualties and twice as many slightly injured casualties attending hospital as a result of road accidents.²

Average Value of Prevention per Accident ³

Fatal	£1,428,180
Serious	£160,480
Slight	£12,370
Average, all casualties	£44,920
Damage only	£1,710

(including an allowance for damage only accidents)

Each accident generates a substantial cost in terms of resources, lost production, health-care, social benefits and in personal pain, grief and suffering. Road accidents have been estimated to cost the country over £16,000 million per year.

The average value of preventing accidents is contained within Highways Economic Note 1. This information is an essential point of reference for engineers when assessing the cost/benefit ratio of casualty reduction or accident prevention schemes.

What Can Engineers Do About The Road Accident Problem?

All civil engineers working within the highway and transportation environments are ideally placed to make a significant impact in helping to reduce the numbers and severity of road traffic casualties.

There are two complementary approaches to this work - accident reduction and accident prevention.

Accident Reduction

Accident reduction involves measures designed to reduce the number and severity of accidents based on an existing known pattern.

Accident analysis and remedial engineering measures.
An effective road safety strategy and reduction plan.

Accident Prevention

Accident prevention relates to the application of measures to prevent accidents taking place in the future.

Road Safety and User Audits on all new infrastructure or alterations.
Periodic Road Safety Audits on existing infrastructure as an element of the total risk assessment philosophy.
The training of engineers in up to date accident investigation & prevention (AIP)⁴

This fact sheet focuses on remedial engineering measures, primarily because there is a greater potential for engineers to deliver effective accident prevention. The numbers of accidents (and their severity) are still too high and engineers must address this problem by implementing cost effective remedial engineering measures.

In parallel with the increase in engineering remedial measures, a greater emphasis needs to be placed on accident prevention. Which is in essence even more cost effective. Over the next few years Road User and Safety Audits will achieve a greater level of priority; and Road Safety Impact Assessments will be piloted in the UK as part of the planning approval process for infrastructure projects.

Using Low Cost Remedial Engineering Measures to Reduce Accidents

When collating, sifting and sorting data, and diagnosing accident problems it is essential to focus on the many factors which led to them happening in considerable detail.

The four main approaches adopted to reduce accidents by highway engineering measures are:

Single site
Mass action
Route action
Area-wide action

Local Safety Schemes

Local safety schemes (LSS) have been proven to provide the most cost effective means of delivering the necessary level of accident reduction which society has come to expect.

These schemes, in comparison with other construction projects are relatively low-cost (<£100,000), yet the level of funding earmarked for such works across Great Britain does not even equal 1% of the true cost to the economy of all the road traffic accidents.

A greater level of funding should be allocated to local safety schemes, and far greater importance needs to be placed upon them. Their contribution to the creation of a safer environment cannot be understated.

Analysis of Schemes (<£100,000) by Category⁵Key: FYRR - First Year Rate of Return (100% = 1 year)

Category	No. of schemes	Av. Cost £	Reduction in Accidents %	FYRR %
Anti-skid	34	8,620	57	352
Area Traffic Calming	14	46,093	57	216
Controlled Crossing	73	15,916	31	89
Markings	43	2,020	34	957
Markings & Signs	63	2,537	41	820
Refuges	65	10,387	37	259
Package Schemes	97	22,099	42	171
Signal Improvements	16	17,095	22	155
Speed Limits	6	1,117	33	1035
Traffic Calming Horizontal	16	22,606	46	125
Traffic Calming Vertical	58	23,333	65	198
Warning Signs	36	553	46	3491
Speed Cameras	28	18,236	13	260
Junction Improvements	34	18,513	44	168
New Traffic Signals	15	40,717	67	153
Mini Roundabout	18	14,769	49	134
Yellow bar markings to slip roads		1,000	25
Yellow bar markings to roundabouts		1,000	50

References
1. Road Casualties Great Britain : 2006 - Annual Report. DfT.
2. TRL Report 173 Comparison of hospital and police casualty data: national study. 1996
3. Highways Economic Note 1. 2005. (Jan 2007) (HEN 1) DfT.
4. RoSPA - Road Safety Engineering (AIP). Training courses evolved since 1971.
5. Accident remedial measures data courtesy of TMS Consultancy, Coventry and the RoSPA Road Safety Engineering Manual 1995.