12.2 The Importance of Monitoring, analysing and Evaluating
With limited budgets, it is very important to demonstrate that road safety interventions are effective, and of value. This is particularly important in LMICs where comprehensive action plans have been developed fairly recently with limited funds from central governments and aid agencies. and all road safety activities must therefore be monitored to ensure that investments are effective. As each initiative is implemented, the effectiveness of that measure should be monitored, ideally by analysing collision data during specific ‘before’ and ‘after’ periods.
Action plans should set quantifiable targets for numbers (or rates) of crashes and casualties to enable assessment of programme effectiveness. In addition to monitoring numbers of crashes and casualties, a newly established action plan should, possibly under the auspices of a National Road Safety Council (or equivalent), seek to ensure that progress is actually being maintained, in other words, that the various agencies and government departments concerned are actually implementing the improvements outlined in the plan.
Good information is required on the effectiveness of interventions to ensure that limited available funding is spent in the most effective way. There is currently a large gap in the understanding of how different interventions improve safety, especially in LMICs. Intervention Effectiveness in LMICs in Section 11.3 Intervention Options and Selection highlights some of the difficulties in using information from HICs on treatment effectiveness in LMICs. An evidence-based approach is required to improve knowledge on effectiveness of interventions in LMICs, and this can only occur through monitoring and evaluation of interventions in these countries.
From an overall perspective, it is important to identify the impact of a national road safety action plan and to monitor the achievement of any goals that have been set.
CASE STUDY – UK National Safety Target Monitoring
In the 1980s, Great Britain set a national target: by the year 2000, casualties would be reduced by one-third from the average annual values prevailing from 1981 to 1985.
Since then, national statistics have been carefully monitored in order to determine the impact of a wide range of remedial measures, including physical improvements, changes in legislation, etc. The overall effects are summarized in the table below.
| SEVERITY | 1981-85 AVERAGE | 1999 | PERCENTAGE CHANGE |
|---|---|---|---|
| FATAL | 5,598 | 3,423 | – 39.0 |
| SERIOUS | 74,534 | 39,122 | – 47.5 |
| SLIGHT | 241,787 | 277,765 | + 15.0 |
| TOTAL | 321,919 | 320,310 | – 0.5 |
CHANGES IN CASUALTIES – GREAT BRITAIN
The table shows that there have been significant reductions in fatal and serious casualties but an increase in slightly injured. What appears to have taken place in Britain over the last 15 years or so is a very noticeable reduction in the severity of injuries, with little change in the total number of casualties. More detailed analyses indicate changes on roads of different categories and between classes of road users. They also reveal that traffic has increased by over 50% since 1981-85 and that the overall casualty rate (casualties per million vehicle kilometres) has decreased by 37%.
NOTE: Since this success UK has abandoned national targets and in the most recent 10 years (2010 -2020) national figures have fallen by much less!
Even worse than the inefficient use of limited funding is the possible use of interventions that lead to an increase in crash risk. Unfortunately, this situation does occur in public policy decision making, including those regarding road safety, often as the result of poor information, as a result of behavioural adaptation from road users, or from a poor implementation process. It may also occur due to trade-offs in decision making, whereby safety considerations are not given as high a priority as other issues (such as mobility).
Studies on Crash Modification Factors (CMFs) have shown that implementing a specific intervention can sometimes lead to an increase in the overall number of crashes. This can occur when a countermeasure reduces one type of crash but simultaneously increases another. A common example is the installation of traffic signals, which may decrease the occurrence of angle crashes (generally associated with higher severity) while increasing the frequency of rear-end crashes (typically less severe). Information on CMFs can be found, for instance, in the CMF Clearinghouse.
Monitoring, analysis and evaluation is an important component of infrastructure safety management, it need not be undertaken to the same extent for each project. For example, if a safety intervention is implemented in a particular locality that has already been thoroughly evaluated and deemed beneficial, then the requirement for further evaluation may be more limited. Safety treatments that have had little or no use in the locality will need to follow a more thorough evaluation process.