Objective: The Road Safety in 10 Countries (RS-10) project will implement 12 different road safety interventions at specific sites within 10 low- and middle-income countries (LMICs). This evaluation reports the number of lives that RS-10 is projected to save in those locations, the economic value of the risk reduction, and the maximum level of investment that a public health intervention of this magnitude would be able to incur before its costs outweigh its health benefits. Methods: We assumed a 5-year time implementation horizon corresponding to the duration of RS-10. Based on a preliminary literature review, we estimated the effectiveness for each of the RS-10 interventions. Applying these effectiveness estimates to the size of the population at risk at RS-10 sites, we calculated the number of lives and life years saved (LYS) by RS-10. We projected the value of a statistical life (VSL) in each RS-10 country based on gross national income (GNI) and estimated the value of the lives saved using each country's VSL. Sensitivity analysis addressed robustness to assumptions about elasticity, discount rates, and intervention effectiveness. Results: From the evidence base reviewed, only 13 studies met our selection criteria. Such a limited base presents uncertainties about the potential impact of the modeled interventions. We tried to account for these uncertainties by allowing effectiveness to vary ±20 percent for each intervention. Despite this variability, RS-10 remains likely to be worth the investment. RS-10 is expected to save 10,310 lives over 5 years (discounted at 3%). VSL and $/LYS methods provide concordant results. Based on our estimates of each country's VSL, the respective countries would be willing to pay $2.45 billion to lower these fatality risks (varying intervention effectiveness by ±20 percent, the corresponding range is $2.0–$2.9 billion). Analysis based on $/LYS shows that the RS-10 project will be cost-effective as long as its costs do not exceed $5.14 billion (under ±20% intervention effectiveness, the range = $4.1–$6.2 billion). Even at low efficacy, these estimates are still several orders of magnitude above the $125 million projected investment. Conclusion: RS-10 is likely to yield high returns for invested resources. The study's chief limitation was the reliance on the world's limited evidence base on how effective the road safety interventions will be. Planned evaluation of RS-10 will enhance planners’ ability to conduct economic assessments of road safety in developing countries.