Safety Treatment of Roadside Parallel-Drainage Structures

摘要

The purpose of the research was to develop traffic-safe end treatments for parallel-drainage structures that would not appreciably restrict water flow. Guidelines or warrants for use of the end treatments were also developed. Parallel-drainage culverts are used to convey water under driveways, side roads, or median crossovers. Preliminary designs were first evaluated using a computer simulation program and a full-scale test program. From these studies, tentative design parameters were selected, including the ditch and driveway slopes and the grate spacing. The end treatment developed in the preliminary studies was then subjected to full-scale prototype testing. These tests involved evaluation of the end treatment on a 6.7 to 1 driveway slope with a subcompact automobile. The end treatment was subjected to tests at 40 mph (64.4 km/h) and 50 mph (96.5 km/h). A benefit/cost analysis was conducted to determine warrants for the use of the treatments.