We’ve talked a bit about barriers in a previous post. The focus there was mostly on cable barriers, as they’re relatively new on the scene. But there are many other types we use to separate traffic and keep travellers safe, like CMB – that’s engineer shorthand for concrete median barrier – that low concrete wall you often see in the middle of a highway.
These barriers last a long time and require little maintenance, even through a collision. They’re a great way to divide the highway and prevent people from drifting across the centre line into oncoming traffic. But before we consider installing barriers, we must assess the area and answer some very important questions, such as:
How wide is the highway?
These barriers are usually about half-a-metre wide at the base. Add another metre to either side to keep traffic at a safe distance, and putting in a barrier could mean we need to widen the highway, which isn’t always feasible.
What about access?
This is something that applies to any kind of barrier, whether it’s concrete, cable or anything else. Physically dividing the highway reduces cross-over incidents, but it can cause problems for local residents and businesses that need to get across the road on a regular basis.
What about emergency vehicles?
Limiting access isn’t just a concern for residents and businesses. Emergency vehicles have to be taken into account, too. If there’s a collision on the highway, traffic can be lined up for a long way, and if there’s a barrier down the middle of the highway, it can make things difficult for emergency services to get to the scene.
One solution has been the use of vulcan barriers — like the one on Highway 19 — concrete median barrier with an emergency access gate. Other types of emergency gates can be found in some parts of the province, such as Kelowna and the Alex Fraser Bridge in Delta.
These are just some of the things our engineers have to look at when we’re thinking about installing barriers like these. But rest assured, they study the highway and traffic patterns very closely to figure out if they’re the best solution to improve safety. They need to make sure a barrier won’t become an obstacle. It can be a fine balance, and one that can vary as regions grow and traffic patterns change, so we monitor our roads carefully to keep them safe.
TranBC Trivia – Our 47,000+ kilometres of road have about 2,100 kilometres of barriers.