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This paper compares pavement texture measurements from a three-dimensional (3-D) line-laser scanner and from a two-dimensional (2-D) spot-laser circular track (CT) meter to determine whether correlations exist between their texture parameters. Measurements with the two devices were taken simultaneously on pavements at the Minnesota Department of Transportation MnROAD test facilities. The 3-D texture heights were decomposed by using a discrete wavelet transform to separate microtexture from macrotexture. Macrotexture parameters from the two devices were analyzed. A linear relationship, with an R2 value of .94, was found between the 2-D mean profile depth and the 3-D digitally simulated mean texture depth. Similarly, the R2 value was .98 between the 2-D root mean square roughness and the 3-D root mean square deviation. These correlations are essential and can be used by road agencies to predict texture indexes between 2-D and 3-D measurements for data comparison or quality assurance when equipment is of different dimensions.

The spring thaw period significantly reduces the bearing capacity of low-volume asphalt roads. To compensate for the reduced bearing capacity, highway agencies apply spring load restrictions (SLR) to limit the damage caused by heavy loads during the period when the road is weakened by thaw. Although the imposition of SLR may reduce road damage, it has a major impact on truck productivity. An alternative to reducing truck loads during the spring is the reduction of truck tire pressure. The reduced tire pressure lowers the tire–pavement contact pressure and the associated damage during the spring period. In 2008, asphalt strain gauges were installed in a section of a low-volume haul road in Manitoba, Canada. Field testing was conducted in the spring and fall of 2009 with a double semitrailer or B-Train equipped with a semiautomated tire pressure control system. The tests were conducted at various loads and speeds and at normal and reduced tire pressures. The results of the field testing showed that when the tire pressure was reduced by 50%, the measured maximum tensile strain at the bottom of the asphalt layer decreased by an average of 15% to 20%. The effects of gauge orientation, truck speed, and tire offset from the strain gauge were analyzed and are presented.

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Coloured pavements have been implemented by metropolitan areas to denote dedicated lanes for bus rapid transit to maintain a high level of safety. Transit benefits of these installations are well documented. However, field performance of various types of coloured pavement has not been investigated systematically, with questions not being answered. In collaboration with the Regional Municipality of York (ON, Canada) where red pavement sections have been in operation for years for its bus rapid transit lanes, the Centre for Pavement and Transportation Technology at the University of Waterloo (Waterloo, ON, Canada) assessed the performance of various types of red pavements including epoxy paint and red asphalt mixes. It was found that, with significant lower texture depth, epoxy paint surface has disadvantages to red asphalt pavement from a pavement texture and safety perspective. The red asphalt sections in this study were observed as lower yet compatible frictional levels to conventional black pavement. Various types of contamination onto the red pavement were observed during field survey. In addition, the ultraviolet radiation degraded the colour of red asphalt pavement over time and may make it less effective for lane designation. Long-term monitoring is recommended to evaluate the functional and structural performance of red asphalt pavement.