MPD/IRI Transverse Position

MPD/IRI Transverse Position


Road monitoring of the state road network in Sweden includes for the longitudinal measurement of international roughness index (IRI) and mean profile depth (MPD). In Sweden the paths of the longitudinal measurements correspond to the surface contact points between the wheels of a light passenger vehicle. This data can be used to estimate values for friction, rolling resistance, comfort and vehicle wear. Knowledge of the surface condition (IRI and MPD) at the surface contact points associated with a large goods vehicle would prove to be useful when estimating similar values for large goods vehicle on an entire or local road network. If these conditions are not measured, it is important to know how they differ from the measured path.

In Sweden, lateral position comparisons made between light and heavy vehicles show that left wheel track positions are similar. This applies to larger and wider roads (typical motorways and other wide main roads). Using this knowledge VTI’s measurement vehicle was equipped with two extra texture lasers which were mounted to the right of the ordinary texture laser in the right wheel track. Data was collected on a road network with mixed categories of road standard, from secondary roads to motorways.

In this talk, we will present a study of the differences of IRI and MPD corresponding to the position of light vehicles right wheel path with two other paths, 25 and 45 cm further out to the right (position of large goods vehicles). We also will discuss the possibility to predict the differences between the tracks. A statistical analysis procedure for calculating the mean difference and an error margin is suggested. The results showed that although it is very difficult to explain or predict local differences, average differences can be estimated.



Swedish organisations in EU project on traffic safety and crash testing

Crash safety testing is one of the tools used to improve safety on roads. The EU is therefore funding a research project that started recently to develop virtual methods of crash testing. The long-term goal is to supplement the physical evaluation of crash...


International Conference on Electric Road Systems starts today

Electric Road Systems (ERS) is a relatively new concept with many initiatives on the way. To learn from each other and stimulate new collaborations the Swedish Research and Innovation Platform for Electric Roads arranged the first international conference...


Same survey of road users’ attitudes in 50 countries

At the Road Safety on Five Continents Conference, RS5C, one entire session presented a large survey of road users' attitudes in 38 countries. Results show large differences between countries in many areas, both regarding behavior and attitudes. A new survey...


Good results with alcohol interlock program according to Swedish study

An alcohol interlock program makes it possible for drink driving offenders to continue their everyday lives. In a Swedish study most of the participants were satisfied with the program and experienced improved health. They also reported drinking alcohol more...


Traffic safety in the spotlight

Today the Conference Road Safety on Five Continents (RS5C) opened in Jeju Island, South Korea. More than 220 participators have come from all over the world to present findings and learn about traffic safety. Dr. Young Tae Kim, Secretary-General of the...


VTI will develop simulators for ambulance staff

VTI has initiated a pilot study for paramedics with the Centre for Teaching & Research in Disaster Medicine and Traumatology and Linköping University. The aim is to give ambulance staff the opportunity to practice critical medical tasks in a moving vehicle in...