An outline for a validation database for SAMGODS

Magnus Johansson

A new Swedish national goods transportation model, SAMGODS, has been developed through collaboration among Swedish transport authorities. As the model recently has begun to be applied to real world problems, the need for a validation database has increased. The purpose of such a database is to facilitate validations of the model. The current paper presents a pilot study to create a validation database for SAMGODS. The study focuses on two areas: available data sources that may provide validation data, and how to carry out the validation in practice. The latter is of particular importance since a large number of practical problems arise when matching SAMGODS output data with the validation data. Worth mentioning among the problems that arise are: the inhomogeneous structure of the data tables, the often differing aggregation levels between model output data and validation data, differing time periods, differing systems for commodity groups and elasticities not being immediately available from the SAMGODS data. Other complicating issues are handling of confidential data and the large quantities of data. In this report, a relatively detailed proposal for the design of a validation database is put forward. However, the proposed design is not limited to SAMGODS output data, but it is hoped to be sufficiently flexible to comprise also other goods transportation data from future regional or local models. One of the main ideas in designing the database has been to develop a uniform and flexible data table format in which all relevant data can be stored. This format greatly facilitates the matching between SAMGODS output data and the validation data. Other problems and associated possible solutions are thoroughly discussed.



ERPUG 2017

The five year anniversary of  European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017. 



Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...


Tomas Svensson new director-general

Tomas Svensson was today appointed Director-General of VTI. Tomas has been acting Director-General since January 2017. 


Crash testing bicycles at VTI

For the first time single bicycle crashes have been simulated at the VTI crash safety laboratory.


A case study exploring firefighters’ and municipal officials’ preparedness for electrical vehicles

A VTI-study presents a social perspective on new vehicle technology. It explores the self-reported preparedness of the fire departments (i.e., rescue services) in Sweden’s three largest cities regarding rescue operations involving electrical vehicles (EVs).


Pioneering research on and about bicycles at VTI

Under what circumstances might cyclists lose tyre grip? What actions could then be taken to prevent a crash? VTI is currently developing a theoretical model of the behaviour of bicycle tyres during braking and steering in different situations and on different...


Virtual pedestrians create efficient stations

If more people are to choose sustainable travel, then the public transport stations of the future must be designed so that pedestrians can get where they are going quickly, without congestion or queues. The Swedish Road and Transport Research Institute (VTI)...