Road surface influence on rolling resistance: coastdown measurements for a car and an HGV


The influence of road surface properties, such as macrotexture and unevenness, on rolling resistance and fuel consumption is an important factor to consider when deter¬mining the coating of a road surface. Results of a VTI study show that the effect of unevenness is in general significantly smaller than that of macrotexture.

The relative smallness of this influence makes measurements of it a challenging task. In literature a wide range of results can be found and there is still much confusion and uncertainty about how large the influence actually is. In this study, an attempt is made to obtain more reliable estimates of how macrotexture and unevenness affect rolling resistance. The primary method used here is the coastdown method. It has been applied to a private car and to a heavy goods vehicle (HGV). Concerning the effect of unevenness on rolling resistance, only the coastdown method provides any information. Results show that the effect of unevenness is in general significantly smaller than that of macrotexture.

The coastdown method provides, besides information about rolling resistance, other useful data for the vehicle, such as air resistance coefficients, temperature coefficients and transmission resistance.



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...


Unique electrified road opens in Sweden

The world’s first electrified road recharging the batteries of cars and trucks while driving opened in Sweden. The Swedish Minister for Infrastructure, Tomas Eneroth, was at the formal inauguration of the electrified road on April 11, 2018. VTI is one of 22...