Document: RTS-2008-2-EN Original: English EU transport statistics Workshop on Road Traffic Statistics Luxembourg, 04-05 November 2008 Bech Building Room BECH QUETELET Beginning 10:00 AM Measuring road traffic volumes Overview of data sources and methods Item 4 of the agenda
WORKSHOP ON ROAD TRAFFIC STATISTICS Luxembourg, 4-5 November 2008 Measuring road traffic volumes Overview of data sources and methods 1. Main defintions The Glossary for Transport Statistics provides the main definitions to be used when measuring road traffic volumes. Two of them should be particularly highlighted here: Road traffic: Any movement of a road vehicle on a given network. Vehicle-kilometre (VKm): Unit of measurement representing the movement of a road motor vehicle over one kilometre. VKm is, therefore, the most commonly used unit when measuring road traffic volumes. However, this measurement is not made by a single method. Each country applies their own methodology using one or several of the main four existing methods 2. The existing methods for measuring road traffic volumes invkm There are four main methods for the collection of data on road traffic volumes: odometer readings, household/mobility/driver surveys, traffic counts and fuel consumption. None of them is particularly recommended. Each method uses different data sources and provides relevant results at aggregated and detailed level. A brief description of the main principles of these four methods follows: Odometer readings from roadworthiness tests. This method relies on the odometer readings taken at roadworthiness tests which are mandatory in the EU Members States. The odometer reading provides the kilometres driven by the tested vehicle in a specific period which are converted into kilometres driven per day. The period in question is either the interval between two successive tests or, lacking data from two tests, the interval between the current test and the first day of use of the vehicle. The kilometres per day are multiplied by the number of registered vehicles to estimate the average daily volume of road traffic. Multiplying further by the number of days in a given year, gives the average yearly volume.. This method relies on regular censuses of road traffic intensity. Measurements are taken in sections of motorways and other major roads and in a sample of sections in regional roads. The measurements in each section are traffic counts, i.e. counts of the number of vehicles passing a point established in the section, within a given period of time. The counts in each section are converted to estimates of annual average daily traffic. The latter is multiplied by the length of the section and the number of days in the year in order to estimate the total vehicle-kilometres. The usual frequency of such censuses is five-yearly. Some countries complement them with measurements taken continuously in the most loaded sections by automatic counters. ESTAT.G5 2/5 RTS-2008-2-EN
Household surveys. This method relies on surveys of households, persons or vehicle owners or drivers, which measure, possibly together with other variables, the use of vehicles and collect, inter alia, the number of kilometres travelled. Such surveys are usually sample surveys. Since they are very often not specific vehicle use surveys, the target population, sampling frame, sample design, etc may differ a lot between national surveys. Fuel consumption. This method aims to provide not only estimates of the volume of road traffic but also estimates of consumption per kilometre and total fuel consumption which are coherent between them and with official national data on fuel deliveries. The method combines vehicle fleet size with estimates of average distance travelled by each vehicle (derived with a different method, e.g. a survey) and obtains an estimate of the volume of road traffic. The latter is combined with data on fuel consumption per kilometre (also derived from surveys or from vehicle reviews) and results in an estimate of total fuel consumption. Annex I is giving an overview of the activities carried out at national level for measuring road traffic volumes. Odometer readings and traffic counts are the two methods more frequently used but, in most of the cases, more than one method is applied to compliment or cross-check the results obtained. This point of the Agenda is devoted to analyse in detail the different methods. Several countries will present their activities at national level as a way to provide a vision, as wide as possible, of the existing possibilities to measure road traffic volumes. ESTAT.G5 3/5 RTS-2008-2-EN
Annex I: Statistical activities for measuring road passenger traffic (vehicle-kilometres) Country Input data for calculation of vehicle-kilometres Remarks Belgium Five-yearly traffic counting Odometer readings and database of registered vehicles (DIV) Bulgaria National survey on Buses and Coaches National survey on Road Freight Transport Czech Republic Road traffic counts Not carried out in urban roads Denmark Odometer readings Official vehicle data Information from the daily mobility survey (TU) may be used to estimate vehicle-kilometres by age and gender of driver for some of the vehicle types (passenger car, motorcycles moped, bicycle) Germany National survey of German goods vehicles Fuel sales and consumption Central information system to toll charged journeys National survey of German buses and coaches Estonia Road traffic counts In driver survey not all traffic is covered. Driver survey (complementarily) Ireland Relevant information can be derived from the National Car Testing (MOT) on odometer readings Greece Until 2001 use of administrative sources and estimates From 2001 onwards no data collection of VKm Spain France Fuel consumption Driver survey and traffic counts Five-yearly goods vehicle survey Italy The use of odometer readings method is under consideration Cyprus Latvia Odometer readings Lithuania Survey on statistics on the carriage of goods by roads Survey on public passenger carried by road E-road Census and Survey on Transport volumes on State Roads outside built-up areas (Road Research Institute data) Luxembourg Relevant information can be derived from odometer readings supplied by the National Technical Control Society Hungary Road traffic counts Malta Odometer readings Vehicle-kilometres are not estimated yet Netherlands Odometer readings Survey of national vehicles on national territory Austria Road Traffic Count Fuel consumption The Austrian National Transport Model Poland Road traffic counts Origin-destination surveys Border s surveys Portugal Survey on Road Transport of goods Estradas de Portugal" (the ruling entity for the national road network) as regards VKm on motorways Romania Road traffic counts For national road network the values are estimated from a demand/supply model. Slovenia Road traffic counts Slovak Republic Road traffic counts Finland National travel survey ESTAT.G5 4/5 RTS-2008-2-EN
Country Input data for calculation of vehicle-kilometres Remarks Sweden For data on national territory: estimating model using as data sources traffic counts, fuel consumption, traffic accidents and vehicle information. For data on national vehicles: odometer readings and vehicle registerer United Kingdom Road traffic counts National travel survey Norther Ireland not included Croatia Road traffic counts FYROM No information Turkey No information Norway Fuel consumption Household survey Switzerland Odometer readings Drivers survey ESTAT.G5 5/5 RTS-2008-2-EN