Johan Granlund

Freelancing consultant

Road roughness create dynamic traffic loads on the pavement as they force heavy vehicles to shake, bounce and roll sideways, instead of rolling smoothly with only static load against the road surface. These dynamic loads add damage to the pavement and shorten the life of the road surface, similar to illegal truck overloads. The shortened service li...

A summary of some experiences made from using laser scanned 3D road profiles in accident investigations in Norway and in Sweden.

Annually, several hundreds of motorcyclists in Sweden are injured after crashing on roads that are slippery due to contamination of loose gravel or diesel fuel on the asphalt surface. The vast majority of loose gravel come from winter gritting, from bad road repair or have been scattered from unbound material at the asphalt edge. Heavy vehicles wit...

Förord Transportstyrelsen har sedan 2013 bemyndigande enligt plan- och byggförordningen, PBF, (2011:338) att föreskriva om tekniska egenskapskrav för vägar och gator. Idag gäller Vägverkets föreskrifter (VVFS 2003:140) om tekniska egenskapskrav vid byggande på vägar och gator (vägregler). Dessa kommer att upphävas i samband med att Transportst...

I Sverige dominerar singelolyckan bland olyckor med svåra personskador. Det sker fem ganger fler singelolyckor I ytterkurvor än i innerkurvor. En orsak är att feldoserat tvärfall är mycket vanligare i ytterkurvor än i innerkurvor. Det finns potential att förebygga uppemot 50 dödsfall och 500 svårt skadade per år, genom att ge relevant varning (skyl...

Relating long wave road unevenness, caused by settlements in the subground, to road vehicle crashes.

This study quantifies and explains the paradox of a slow increase in road quality over time with a concomitant decrease in ride comfort or objective road quality. The study estimates the effect of road profile wavelength contents on the International Roughness Index (IRI) and planar personal half-car model vertical vibration response. Two cases are...

Remixing of the wearing course in the high-speed lane of a freeway resulted in a new road surface that, compared with the old surface in the adjacent low-speed lane, was perceived as a bumpy ride by road users, as well as by the road agency and the paving contractor. In this paper, the unevenness of the longitudinal road profiles of the old and the...

Many bus drivers are exposed to health risks, due to repeated exposure of mechanical shocks when frequently riding over traffic speed bumps. This paper presents recent results from an investigation of vibrations imposed on the driver from some twenty speed bumps in the Stockholm area (Sweden). The vibrations have been evaluated in accordance with t...

Pavement unevenness brings safety risks. One example is that excessive runway roughness impact negatively on winter operations, with increased ice and snow contamination reducing the aircraft´s brake friction. When planning a costly pavement geometry repair, large savings can be made by optimal milling and levelling works. Accurate measurement of t...

A new method for testing pavement condition combines laser/inertial profilometry of unloaded pavement with vibration measurements in a full loaded heavy truck at highway speed. Three types of results are obtained. 1: Truck wheel, frame and cab vibration, as well as driver seat vibration to be compared with exposure guidelines in ISO 2631-1 and limi...

Many road users suffer from back pain, fatigue, drowsiness and motion sickness. Such problems are often related to low frequency vibration. While vehicle suspension systems efficiently isolate vibration caused by road texture and short-wave roughness, they often amplify vibration at lower frequencies. Sources of these motions are large variance of...

Accurate road profiles are useful in vehicle design, such as for simulation of durability and ride quality. Laser/inertial profilometers typically record 1mm wide profiles. The question is how well such a profile matches perceived vehicle wheel roughness. The objective here was to create a more representative wheel track longitudinal profile. Simul...

A new high speed method for testing pavement condition was drafted during 2002. It combines profilometry of unloaded pavement with response measurements in a full loaded heavy truck. Three types of results are obtained. 1: Actual truck ride vibration at selected points and directions; seat vibration to be compared with human vibration exposure guid...

Every road authority targets good ride quality in their pavement management. Ride quality depends strongly on the experienced in-vehicle vibration, induced by road roughness. International Roughness Index (IRI) is the most common way to describe road roughness, while ISO 2631-1 defines how to quantify human whole-body vibration (WBV), experienced b...

Road bumps reduce vehicle speeds on residential streets and other densely populated areas, thus improving safety and comfort for pedestrians and bicyclists. Unfortunately, the effects on health and safety for drivers and passengers passing these obstacles are rarely considered by road agencies, consultants and contractors. Many current bumps induce...

Every road authority targets good ride quality in their pavement management. Ride quality depends strongly on the experienced vibrations, induced by road roughness. International Roughness Index, IRI, is the most common way to describe road roughness. But there exist no commonly accepted limits for IRI. ISO 2631 defines how to measure human whole b...

For rough road sections, traditional pavement maintenance actions such as the 2’’ overlay is quite efficient in reducing ground vibrations, vehicle body noise, rolling resistance and re-establishing bearing capacity as well as a nice looking surface. The overlay is also often efficient in reducing vertical and horizontal whole body vibrations (WBV)...

2007 he became certified Senior Project Manager by IPMA. He joined Swedish Road Administration (SRA) as Pavement Engineer in 1991. During 17 years, he served in a handful of positions at SRA. In 2009 the Swedish State created the transportation infrastructure company Vectura Consulting AB. Johan's position at Vectura is Chief Technology Officer for...