23 May 2006
The limits of design
There's been a lot of second-guessing around town since an eighteen-wheeler jumped into the median and through the cable barrier on the Lake Hefner Parkway today. The truck hit an oncoming car, killing the driver of that car; a second car crashed into the truck.
The question for some is whether the cable barrier, manufactured by Brifen and discussed here, is inadequate to the task. I don't think it is. Granted, it didn't hold back the truck; on the other hand, had the truck met the usual concrete Jersey barrier, it likely would have bounced back into its lane and hit more cars. ODOT's Faria Emamian noted that the cables have taken some 400 hits since their installation in 2001, with no secondary collisions from bounceback; in the three years before the cables were put in, there were six crossover fatalities on the Hefner.
Short of filling up seven miles of median with foam, I really don't see what could have been done to ameliorate matters.
Posted at 8:32 PM to City Scene
Crossovers sadly are going to happen, no matter what precautions you take, imho. I have seen semis' jump concrete barriers before here in Dallas. I have also almost hit a tire and half an axle from a car that smashed into a concrete barrier on the other side, and it flew over in my path.
Growing up in OKC, and in my visits there, with the exception of I-40 and I-35, I see very few semis. I still believe the cables along the Parkway are well worth it, considering the number of crossovers they have prevented. It's hard to stop a semi with anything.
There was a spectacular 18-wheeler crash near Newnan a couple of weeks ago. The truck swerved across two lanes of traffic, sideswiping a vehicle, and ran head-on into a bridge piling. Truck parts were strewn all over the highway, but the only serious casualty was the driver.
Nothing has been reported on the advanced stages of the investigation, but if I were to guess I'd say the driver discovered a catastrophic mechanical failure and took the quick way out in a manner that would spare as many others as possible.
The people stuck in the highway closure for several hours probably were not as appreciative as they ought, but...