Video Evaluation of Highway Drainage Systems, HR-317, 1991

Since 1978 the concept of longitudinal edge drains along Iowa primary and Interstate highways has been accepted as a cost-effective way of prolonging pavement life. Edge-drain installations have increased over the years, reaching a total of nearly 3,000 mi by 1989. With so many miles of edge drain installed, the development of a system for inspection and evaluation of the drains became essential. Equipment was purchased to evaluate 4-in.-diameter and geocomposite edge drains. Initial evaluations at various sites supported the need for a postconstruction inspection program to ensure that edge-drain installations were in accord with plans and specifications. Information disclosed by video inspections in edge drains and in culverts was compiled on videotape to be used as an informative tool for personnel in the design, construction, and maintenance departments. Video evaluations have influenced changes in maintenance, design, and construction inspection for highway drainage systems in Iowa.

Video Inspection of Highway Edgedrain Systems, HR-317, 1998

Minimizing infiltration of water in pavement structures has long been a priority of pavement designers. Incorporation of subsurface edgedrains is frequently an integral part of an pavement drainage system. In order for such a system to be effective however, it must be properly installed and maintained. With advances in video technology, inspection of edgedrain systems can now be conducted quite efficiently. This report documents the results of 287 video inspections of highway edgedrain systems in 29 states. These inspections were conducted to both demonstrate the capabilities of the technology as well as demonstrating some of the common problems associated with the performance of edgedrain systems. Findings indicated not only that the equipment was quite effective in identifying edgedrain performance concerns, but also how widespread the concerns of edgedrain performance are. Almost one third of the systems inspected had nonfunctional outlets, another third were either found to have non-functional mainlines or the mainlines could not be inspected due to physical obstructions. Only one third of the systems inspected were found to be performing as intended. Recommendations are provided for edgedrain design improvements to facilitate performance of the system and their inspections as well as recommendations to improve quality control during construction. Suggestions are also provided for maintenance procedures to address concerns identified in the inspection process. A Draft Guide Specification For Video Edgedrain Inspection and Acceptance is also provided as an Appendix.

The Traveler, November,2001

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Iowa Department of Transportation Major Items - Preliminary Quantity Report, January 20, 2016; With Addendums

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