Full-Lane Coverage Micromilling Pavement-Surface Quality Control Using Emerging 3D Line Laser Imaging Technology

Abstract

Facing pavement preservation challenges as a result of funding shortages, the Georgia Department of Transportation (GDOT) has developed an innovative micromilling resurfacing method to cost-effectively preserve its pavements. The cost saving is significant: approximately $60,000 per lane mile. To ensure that a smooth micromilled surface texture provides a good bond and water runoff capability, which is the key in this new method, a new, stringent ridge-to-valley-depth (RVD) specification has been established for quantitatively evaluating micromilled surface quality. This paper explores the possibility of using emerging three-dimensional (3D) line laser imaging technology to develop a full-lane quality control method that can measure RVD, provide quality control covering a full lane, and identify problem areas. A lab test was first conducted to critically assess the accuracy of the proposed method by using an artifact: a wood panel with V-shaped grooves of a known depth to simulate the ridges and valleys on a micromilled surface. Results show that the proposed method is very promising and can measure RVD with an error of less than 0.4 mm (0.016 in.). A field test was conducted by using Georgia Tech’s sensing vehicle to collect 3D range data at two 0.8-km (0.5-mi) segments on a micromilling resurfacing project on I-95. Results show that the RVDs in the transverse direction can effectively and quantitatively differentiate between smooth (mean