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Since You Asked: ODOT began using cable barriers 20 years ago Sunday Feb 19, 2017 at 12:01 AM Feb 19, 2017 at 5:58 PM The three-cable barrier system in place on much of Interstate 5 in Oregon is supposed to keep vehicles from crossing over the median into oncoming lanes of traffic. Last weekend, I saw a stretch near milepost 256 that had been completely flattened, which made me wonder just how well the system works. I also wonder why the barrier is often as close as 8 feet from the edge of the highway, rather than in the center of the median. It seems vehicles hitting a barrier right next to the road could bounce back into traffic, which could cause, rather than prevent, a serious accident. One possible reason I've heard is that the median could be wetlands needing protection. How could the median be wetlands if the highway on both sides of it is not? — Tom the Traveler, via email Tom, more than 20 years ago, the Oregon Department of Transportation began using cable barriers to prevent deadly crossover crashes and rebound crashes, which, as you accurately described, occur when a vehicle hits the barrier and bounces back into traffic. Since then, cable barriers have replaced concrete barriers and steel guard rails in many areas along I-5 where opposing lanes are at different elevations or separated by a median of less than 100 feet. ODOT spokesman Gary Leaming says the cable barrier acts as a rubber band so that when it is struck “the energy from the vehicle is distributed through the cable so that the driver is not killed or propelled into oncoming traffic.” Cable barriers, Leaming said, are placed at least 12 feet from the fog line and are projected to deflect a vehicle no more than about 9 feet. Some cable barriers are located farther from the fog line — for example, in the snow zone just south of Exit 14 — to give drivers room to chain up. ODOT also tries to be mindful of maintenance crews, while avoiding any wetlands that exist, by installing cable barriers within the rock shoulder to give crews room to mow, Leaming added. Tom, we can’t say why the stretch of cable near milepost 256 was downed, but it has most likely been fixed since your last trip north. Leaming said cable barriers are relatively easy to fix by replacing any damaged posts, restringing the wire and tightening it. There currently are sections of cable barrier in southwest Oregon between mileposts 131 and 133, mileposts 60 and 61, mileposts 44 and 48, and mileposts 11 and 19. (ODOT has plans to extend the latter stretch to Exit 27 later this year.) — Send questions to “Since You Asked,” Mail Tribune Newsroom, P.O. Box 1108, Medford, OR 97501; by fax to 541-776-4376; or by email to [email protected]. To see a collection of columns, go to mailtribune.com/youasked. We’re sorry, but the volume of questions received prevents us from answering all of them.