Inventory models are tools used to monitor progress towards emission targets, for example targets set in international agreements such as the Convention on Long-range Transboundary Air Pollution (CLRTAP) convention and the UN Paris Agreement on climate change. Moreover, inventory models coupled with economic models estimate the impact of future policies and produce cost benefits analyses.
Emission factors are the core of any transport inventory model. Therefore, accurate emission factors are indispensable for building reliable transport emission inventories.
Emission factors are determined by averaging a large set of measurements undertaken in each vehicle category. These are then used in vehicle simulation models to extend the information contained in the measurements.
The models overseen by the ERMES group are based on a common set of measurements to produce consistent emission factors and emissions estimates. The ERMES emission factors are fed into most widely used European inventory models.
Collaborations on the use of other models are also in place.
COPERT is the EU standard vehicle emissions calculator. It uses vehicle population, mileage, speed and other data such as ambient temperature and calculates emissions and energy consumption for a specific country or region.
PHEM is a detailed model for 1Hz simulation of single motor vehicles and vehicle fleets.
VERSIT+is a suite of models is used to predict emission factors and energy use factors that are representative for vehicle fleets in different countries. Emission factors are differentiated for various vehicle types and traffic situations, and take into account real-world driving conditions.
HBEFA provides emission factors for all current vehicle categories (PC, LDV, HGV, urban buses, coaches and motor cycles), each divided into different categories, for a wide variety of traffic situations
The European Research for Mobile Emission Sources (ERMES) is a group of research institutions, competent authorities, industry associations, whose mission includes the support of cooperative research in the field of transport emission modelling, policy, and practice.