High Tension Cable Barrier (HTCB)
A High Tension Cable Barrier is a roadside barrier that consists of 3 or 4-strand high tension cables that is designed to contain and redirect vehicles that leave the road. These barriers prevent serious collisions on high traffic highways by reducing the number of vehicles that cross the median into oncoming traffic.
Benefits of the HTCB
- Prevents serious cross over median collisions
- HTCB are designed to “give” and absorb the impact of the hitting vehicle rather than bouncing and re-directing it back into traffic. The hitting vehicle tends to travel along the cable barrier until it comes to a stop
- This results in: less damage to the vehicle, less severe injuries to vehicle occupants
- Majority of vehicles that strike the HTCB are able to drive away. Approximately 94% of the collisions with the barrier result in property damage only. In addition, a little over 10% of the recorded hits with the barrier did not result in a collision report being filed.
- HTCB can retain much of its tension after a hit, and can take additional hits until repaired.
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Provincial Cable Barriers
- Highway 2 – From Airdrie to North of Red Deer
- Highway 2 –Through the Leduc area
- Highway 2 – Deerfoot Trail through Calgary
- Various highways are now using cable barrier to replace traditional guardrail installations along the side of the road
Highway 2 Cable Barrier by the Numbers: From Airdrie to North of Red Deer
|Severity of Collision||Collision by Distribution Actual (2001-2005)||Collision by Distribution June to December 2010|
|Property Damage Only||61.1%||93.4%|
Placement of the Cable Barrier
One of the most common questions regarding the cable barrier is: why is it installed in the middle of the median in some places and closer to the shoulder of the road in others? The installation of the barrier is based on two key components, strength and safety. The cable barrier system is strongest when it is installed near the top of the slope of the ditch, not at the bottom. Placement of the barrier also plays a role in the safety of the system. Installation location provides distance from the yellow shoulder line and accounts for any deflection of vehicles striking the barrier.
Figure 1. Placement of the cable barrier in the center of the median
Figure 2. Placement of cable barrier along the shoulder of each lane.
The HTCB is designed to restrain buses, semitrailers and long combination vehicles along with regular commuter vehicles. Since the installation of the HTCB in 2010, there have been no reported cases of a semi-trailer or other large vehicle breaking the barrier.
What to do if you hit the cable barrier:
If you strike the cable barrier and are not injured and your vehicle is still driveable you should drive the vehicle off the highway if safe to do so. You can then report the collision to your local RCMP Detachment or Police Station at your earliest convenience.
If you strike the cable barrier and are injured and/or the vehicle is not driveable, you should dial 911 immediately and remain in your vehicle unless an aggravating circumstance exists such as fire or a presence of hazardous materials, etc. prevents you from remaining safe inside the vehicle. You should remain belted and inside your vehicle until emergency first responders arrive.
Testimonial from a First Responder
I have been working exclusively on Highway 2 as an RCMP Constable for the last 4.5 years. I have responded to hundreds of collisions in all weather conditions of varying severity, both prior to the installation of the cable barrier and after the installation of the cable barrier. I can say without hesitation that the cable barrier has reduced our injury and fatal collisions, and has created a safer driving environment for all Albertans traveling on our busiest section of roadway. Prior to the installation of the cable barrier, it was commonplace (typically in inclement weather) to have vehicles lose control, cross the centre median and enter the oncoming traffic lanes posing an elevated risk of serious injury or death to all involved parties. Head-on and front off-set collisions present a higher likelihood of serious injury or death, especially at Highway speeds and the cable barrier effectively reduces the possibility of these occurrences. The cable barrier provides a much needed safety net of separation between north and southbound traffic, and I am thankful that it also provides another layer of security to first responders who are often placed in harm’s way while in the course of their duties on Highway 2.
Cst. Chris Warren
Highway 2 Integrated Traffic Services - Red Deer
Additional information can be found by following the below links.
Q and A (pdf 140 KB)
Motorcyclists and High Tension Cable Barrier (pdf 138 KB)
Summary Report (pdf 31.6 MB)
High Tension Cable Barrier Performance Evaluation Summary (pdf 3.13 MB)
Shoulder vs. Ditch Analysis Technical Memo (pdf 275 KB)