Methodological notes: Global vehicle sales database
Over the past decade, a number of markets have adopted regulations to reduce fuel consumption and emissions of greenhouse gases and conventional pollutants from light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs). The ICCT has undertaken several global studies to determine the impact and status of these standards in major vehicle markets (Façanha et al., 2012; Chambliss et al., 2013; Miller et al., 2014; Kodjak, 2015).
In this paper, we explain the methods used to construct a global database of historical vehicle sales and facilitate the development of sales-based metrics that track progress toward clean vehicle policies and technologies.
This paper offers three main conclusions:
- Reclassifying new vehicle sales by regulatory category enables appropriate comparisons of the coverage of policies and technologies for LDVs and HDVs that would not be possible using OICA sales data alone. For example, LDV efficiency regulations in the U.S. covered 16.5 million LDVs in 2014, nearly 20% of global LDV sales. If this comparison had been made using passenger cars (PC) as a proxy for LDVs, the U.S. regulations would be estimated to cover less than 12% of global sales.
- There remain opportunities to improve the database in future work. Information on the share of sales by fuel type is sparse among global data sets, and this information is not yet available for all markets or for all calendar years. Additionally, there are gaps in sales data for PC and LT/LCV in many small- and medium-sized markets. The database should be updated as data for additional years become available (i.e. 2015).
- Comparisons of the share of vehicle sales subject to regulations will be especially robust to the extent that they relate to the regulations adopted in top markets (for example, the share of sales in markets that have world class emissions standards). There remains a need to collect and validate policy information for small- and medium-sized markets, including the specific vehicle types covered by such policies.