The Vehicle Stock module (VES) converts passenger and freight demand to vehicle fleet size, which is disaggregated to vehicle type and vehicle age cohort for calculation of emissions and energy use. Vehicle types include propulsion and fuel technologies, and the module includes 61 road and 12 non-road vehicle types. The vehicle age cohorts range from 0 to 29 years.
Fleet stock forecasts are provided at country and region for each of the 28 EU Member States and for each period (5-year intervals) up to 2050. The module also delivers forecasts of average fixed and variable generalised costs for each vehicle type, and total tax revenue per country.
The main input is transport demand in the previous period of (t-5). This 5-year gap is compensated by multiplying this transport demand by a factor, which is the ratio of vehicle stock data in period t to vehicle stock in (t+5), which is estimated from transport demand of period t.
This input and the detailed vehicle stock in period (t-5) including the number of vehicles in period (t-5) that survived in period (t) are used to calculate the average number of kilometres per vehicle calculated for the period of (t).
The demand for new vehicles in period t is the difference between the surviving vehicle stock and the estimated demand for period (t-5) multiplied by the factor.
The logit and the stock dynamic model inside the Vehicle Stock module use the calculated average generalised costs to define the shares of the different types of new vehicles entering the market as well as their numbers. This calculation produces the detailed existing vehicle stock in period (t).