scanny77 wrote:
2. i saw the aftermatch of an rta this morning. i dont know which way it was going but a car made a mess of the wire supports and came to rest in the middle lane facing the wrong way. how is that better than the old type and why arent they using concrete blocks across the network instead of only certain places?
The 'supports' are sacrificial. The wires are designed to catch the vehicle and are positioned at the appropriate height. Again this is exactly the same with armco. The supports offer no lateral restraint.
The concrete block thing is due to cost and also I'd rather have a soft impact than a hard impact. Concrete barrier tends to be where you really REALLY don't want the vehicle passing through and also where there is a reduced central reserve. You often see them at bridge supports and the like or Open Box Beam or Double OBB.