Both the Delta and RetroTek systems are capable of carrying out surveys at normal road speeds, eliminating the need for road closures/traffic management.
Independent tests have verified that the RetroTek-D accurately measures in day or night the night visibility RL (coefficient of retroreflected luminance) of pavement line/striping markings to CEN En 1426 & ASTM E 1710 & as accurate as hand held retroreflectometers. The system also counts the presence and absence of Pavement Markers (RPMs)/ road studs and centre median barrier reflectors. RetroTek-D uniquely measures the retroreflectivity (RL) of both right and left longitudinal lines (edge and centre lines) and centre lane marking/symbols. This is not possible for side mounted systems without road closure/traffic management & multiple survey passes.
Both systems can accurately measure the daylight contrast ratio between the road surface and the road markings. The RetroTek-D has built-in auto-exposure to compensate for bright sunlight, shadows, road glare and vehicle bouncing from uneven road surfaces and driving behaviours (accelerating/braking).
The Delta and RetroTek systems both use GPS to accurately record the locations where measurements have been taken, and where markings have not met retroreflectivity requirements. This allows road maintenance authorities to efficiently plan road marking maintenance efforts.
Both systems offer repeatability of +/-3%, and reproducibility of +/-5%, making them extremely competitive to handheld instruments.