Most estimates for the projected global burden of road traffic injuries have come from the World Health Organization’s Global Burden of Disease Study.1 There are acknowledged limitations of these estimates, including the under-enumeration of in-country mortality for particular causes of death and the variation in the estimates generated for countries with limited mortality reporting systems or few stratum-specific cases or causes of disease/injury.2 Despite the limitations, the estimates highlight that the disproportionate burden of road traffic injury is currently, and will continue to be, borne in low-income and middle-income countries.34 As a consequence, these countries need to develop or enhance their systems or approaches for identifying, monitoring and measuring this significant public health issue in order to set national priorities for prevention.

The suggestion that low-income and middle-income countries need to invest in systems to enumerate the burden of road traffic injury is not straightforward. The resource implications are so significant that, for many low-income countries, it would require substantial development assistance. Such assistance is often very prescriptive and, as a report from the Council on Health Research for Development recently indicated, is generally determined from outside the country of interest and is seldom based on the health priorities or needs of the country.5 As a consequence, what often develops is a plethora of externally funded surveillance systems linked to specific short-term projects, and the systems are seldom evaluated in terms of their ability to document the burden and are not primarily concerned with leaving behind sustainable national (or regional) reporting systems capable of reliably measuring the burden of road traffic injury.

One promising alternative, particularly in low-income and middle-income countries, is the development of metrics that allow existing data sources in a country to be combined in order to develop reliable national estimates; this approach is akin to the current work being developed by the road traffic injuries metrics group at Harvard’s Initiative for Global Health.6 Along similar lines, the paper by Huseyin Naci and colleagues in this issue of the journal (see page 55)7 synthesises studies and data sources (including vital registration or national-level injury surveillance systems) on country-specific road traffic injuries. Both approaches highlight the utility of collating existing information sources in order to provide a cross-sectional view of the burden of road traffic injuries.

Despite the utility of collating existing information sources (eg, vital registration systems, crime data, health surveys, hospitalisation data, police data) for road traffic injury, there are substantial problems associated with establishing the necessary metrics. For low-income countries, these include how to combine multiple estimates for the same country and how to combine poor-quality data in which numerous cases have either no (or poorly specified) causes of injury? These problems, coupled with the fact that most of the data sources are difficult to access and those that are available in low-income countries are not nationally representative, make estimating the global burden of road traffic injuries a challenge.

Despite the difficulties, it is important to not lose sight of the purpose of measuring the burden of road traffic injury—namely, that estimating the national or global burden informs government and non-governmental agencies about areas for funding, research, policy and, importantly, preventive strategies. The last of these is of significant interest given that considerable effort needs to be focused on the implementation of cost-effective preventive strategies, globally. An important point in relation to this is that it is not enough merely to focus on the distribution of the global (or national) burden of road traffic injury and therefore strategies targeting the leading cause, particularly if the known interventions for the strategy have marginal efficacy and are of considerable cost. Rather, it is necessary to consider known cost-effective interventions that can be translated to fit the country context. There are already an array of cost-effective interventions ranging from traffic calming to reduce speed (US$5 per disability-adjusted life years saved) to motorcycle helmet legislation (US$467 per disability-adjusted life years saved).8

There is no doubt that considerable effort is needed to convert the findings from the road traffic injury metrics group or the work reported by Huseyin Naci and colleagues into tangible reductions in the burden. There are opportunities in low-income and middle-income countries to bypass interventions that have contributed little to reductions in road traffic injury in high-income countries and, by doing so, reach reductions in road traffic injury faster than has been the case in high-income countries. For example, the challenge China currently faces with the ready adoption of road network systems from high-income countries is that they are not always appropriate for the country’s traffic mix (which is still predominantly vulnerable road users such as children, pedestrians, bicyclists and motorcyclists). Consequently, a mega city such as Beijing—which once provided separate lanes for bicyclists and other vulnerable road users, thereby separating the vulnerable road users from the motorised vehicles and hence the risk of injury—has now rapidly engineered these lanes out of the road infrastructure. The irony of this is that the high-income countries, which advocate and support rapid motorisation in countries such as China, are attempting to re-engineer their own road systems in order to separate the vulnerable road users and to provide networks conducive to alternative transport modes, particularly those that will encourage physical activity (given the rising prevalence of obesity) and at the same time reduce greenhouse emissions.9

More than 30 years ago, Hart10 described the inverse care law in which market forces lead to the best available healthcare being delivered to populations who least need it. Parallels with the inverse care law can be drawn from the investment in reporting systems for road traffic injury—namely, the best systems are available in countries that have the least burden, and investment, when provided to low-income and middle-income countries, has often contributed little to sustainable national (or regional) reporting systems capable of reliably measuring the burden of road traffic injury. Approaches to obtaining suitable metrics that enable the collation of existing data sources in low-income and middle-income countries are a positive move towards providing a cross-sectional view of the burden of road traffic injury in these settings. More important, however, is the need to harness the resources and efforts currently in place to establish methods for measuring the burden to ensuring that sufficient capacity is provided in-country to guarantee that the system remains ongoing. In fact, even greater effort is needed to ensure that the data contribute to policies and interventions that focus on road traffic injury prevention within the broader context of public health, and not just transport.