Capturing the Car Usage for a One Year Period to Evaluate the Suitability of Battery Electric Vehicles – a Model Based Approach



Capturing the Car Usage for a One Year Period to Evaluate the Suitability of Battery Electric Vehicles – a Model Based Approach

Authors

Christine Weiss, Institute For Transport Studies, Bastian Chlond, Karlsruhe Institute Of Technology (KIT), Michael Heilig, Peter Vortisch, Karlsruhe Institute Of Technology (KIT)

Description

A methodology to capture the daily car mileage over a period of one year is developed. Travel data of the German Mobility Panel (MOP) and of the long distance travel survey INVERMO are used and combined in their evidence.

Abstract

The German Government targets to increase the electric vehicles' share in Germany to 1 million in 2020. However, the penetration of electric cars in Germany is very low at present: in 2012 there were only 4,500 battery electric vehicles and 47,600 hybrid vehicles registered in Germany. The low driving range of battery electric vehicles is usually considered as relevant reason. In order to verify this assumption, the usage of conventional cars in Germany needs to be analysed. These analyses may help to make more reliable and realistic statements to what extent German cars could be replaced by battery electric cars without any restrictions for their users. Most travel surveys do only consider a single day or a short period of time, e.g. one week, in the analysis. However, the daily car usage is not identical over a certain period because the car owners use their car for daily routines, e.g. commuting to work as well as for rather seldom events such as holiday trips. Consequently, longer time periods should be taken into consideration when analysing the travel data.

For closing this gap of knowledge different data sources are used and combined in their evidence:
1. The German Mobility Panel (MOP): Since 1994 each year members of about 1,000 households have been reporting their daily mobility patterns over a period of one week. The survey is carried out in autumn each year. The survey collects data about all trips of the household members including start and end times, trip purpose, distance and means of transportation used. Moreover, socio-demographic data of households (e.g. number of cars per household, net household income or type of the household) and household members (e.g. sex, age, status of employment or driving license ownership) are collected. In addition, the car-owning households within this sample are asked to participate additionally in a car mileage and fuel consumption survey (TANKBUCH) during eight weeks in spring allowing to combine the information of the mobility survey as well as of the Tankbuch-Survey on an intra-household base. The survey participants report all dates and mileages between any refuelling stops as well as the total car mileage and fuel consumption. Car related information such as fuel type, car segment and car engine power are additionally collected.
2. The long distance travel survey INVERMO (INterMOdale VERnetzung) is furthermore used in order to gain comprehensive information on the characteristics of long distance car trips, such as trip length, trip purpose, length of stay at the destination and daily mileage at trip destination. Detailed information about 12,000 long distance car trips were conducted in the survey including the socio-demographic data of the travellers.

The model aims to obtain the mileage of cars for each day in the survey period of one year: As a proxy for everyday mobility, the MOP data of the survey participants for one week are used to cover the daily mobility. In order to calculate the daily car mileage in the MOP-week, a methodology to convert individual travel diaries into a vehicle-based diary by appropriate rules using plausible and consistent assumptions is developed. The refuelling survey is used to identify the frequencies, duration and trip length of long-distance journeys. The INVERMO survey is additionally used to derive information in which way cars are used in long distance travel (e.g. typical trip length distributions by different socio-demographic and socio-economic groups).

As a result the frequency distribution of mileage per day for each car can be derived for a period of one year. Furthermore the car usage and household characteristics of the car-owners are analysed in order to investigate which part of the car fleet could be replaced by electric vehicles.

The presented research is done within the project EVREST (Electric Vehicle with Range Extender as a Sustainable Technology). The EVREST project is a transnational European project carried out in the framework of the ERA-NET Electromobility+ Call. The main idea of this project is to study how Electric Vehicles (EV) with a Range Extender (RE) could match the different usage patterns and what would be the impact of such a solution.

Publisher

Association for European Transport