Bounce back to blacktop.
Like boxers and wrestlers in the ring, cable barriers help you
bounce back to safety.
New and improved cable barriers are saving more lives than expected since installed along a few areas in the Vancouver region.
While considering this road safety tool, Seattle was used as a case study. This area had tried cable barriers but without much success. Upon closer examination, you could see why -- they used an older style cable system with only one or two cables that proved insufficient for deflecting cars back onto the road. We learned from their mistake and innovated with a four-strand cable.
Location I: Harrison Lake
These new and improved cable barriers were installed in two locations in the Fraser Valley. This was a partnership with ICBC and the BC Ministry of Transportation and Infrastructure, and one of my recommendations. There had been a few vehicles go off road right on Rockwell Drive at Harrison Hot Springs. On more than one occasion the vehicle drove off the road and into the lake. Some did not survive and drowned in the lake.
With this knowledge, Harrison was selected as the first candidate to test the cable barrier. A small stretch of road was identified and a cable barrier was installed in 2010 -- since then nobody has died.
Location II: Chilliwack, BC
The second location we tried was the Trans Canada Highway (Hwy 1) at Chilliwack, BC. This site has a very narrow median between the 4 lanes of east and westbound travel. Many times there were cross over head on crashes causing fatalities. We wanted to test this section of highway but there were some logistical challenges.
This area usually has a great deal of rainfall causing water runoff and irrigation concerns. Plus, some of the median ditches are at a steeper grade for this run off, which causes two problems: 1) Vehicle enter at a steeper than recommended angle causing them to flip over the cable; 2) Vehicles enter at an angle that lets them slip through the cable entirely.
The first section of cable barrier was installed and some of the above concerns were observed and reported on. The cable was getting struck more than expected causing a great deal of down time for repair and lane closures. Even so, there was soon demand for an extension of the cable barrier further east of Chilliwack -- in an area where the median is even more narrow.
This secondary area was getting struck even more frequently. The logistics were noted that the inside (fast) lane failed to have a safe recovery shoulder for a driver to negotiate back into their lane. At most of this section the inside shoulder was only 5 or 6 inches. This prompted the highway maintenance contractor to install a narrow rumble strip on the fog line. This appears to have done the trick and less vehicles are hitting the cable.
These four-strand cables had improved success -- partly due their increased strength, and partly due to the weaving system that was used for even better support.
For the most part it works well although heavy commercial vehicle traffic can blow through this pretty easy. Not to mention, concerns from motorcycle groups.
In one of my talks to a motorcycle group about the cable barrier, they were incensed that they were not consulted on this for their safety. They said the cable would slice them up like a cheese grater. I advised them that hitting an over pass abutment or an oncoming car doesn't look any better and most motorcycle collisions outside of urban areas are off road right collisions -- and usually due to speed. Furthermore, most motorcycle clubs aren't known for their communication skills with the highways department 🤔.
Overall, this program has been a huge success -- saving thousands of lives and funding a partnership between ICBC Road Improvement and the Ministry of Highways in B.C.
Watch for these cable barriers anytime you're driving through Chilliwack -- just don't get too close.