Have you ever driven along a freeway and noticed, during the snow season, on the grade separation carrying a secondary road over you that there is orange snow/safety fence tied to the bridges hand railing?
That was my idea.
During the 70s, the Ontario Ministry of Transportation (formerly Dept. of Highways) used to tie old information signs (basically plywood sheets) to their bridge rails to prevent any snow from being plowed off their overpass bridges onto traffic below. As we, the industry had been getting better at deicing and plowing, this snow had become chunkier & harder and could cause problems to the freeway traffic.
The Ministry’s solid sheeting kept the chunks off the traffic below, but also prevented loose snow from getting off the bridge. As the snow accumulated up against the barrier, the road width narrowed creating the need to load and haul it away.
The County I worked for, tucked here in a far east corner of our Province has a long very rural network of roads to administer. We didn’t have the resources nor time to go out and truck snow off bridges on demand. Where we could, our plow operators pushed (often with speed) it through (or even over) any railing as often as they could. As mentioned earlier, this plowed snow could be chunky. Not a problem over streams and ravines, but becoming a problem over other highways.
About that time, manufacturers started producing the ubiquitous plastic snow/safety fence you see at any construction site. An AHA moment. I wondered if we could use it on our overpasses. This stuff was light (old wooden snow fence was heavy), easy to store (the old snow fence was bulky and required more storage room than we had), durable (the old wooden slat fence was more prone to breakage and other damage than you’d think). None of us had seen the plastic fence used on bridges anywhere else, but its time had come. The foremen were willing to try and the men figured out how best to install it.
By putting this open weave snow fence up on our bridges carrying traffic over freeways, the benefits would be widespread;
1. We could plow loose snow through the openings (no more problem to the traffic below than a slight snow squall
2. The fence would stop the chunks from getting down and possibly adversely affecting the traffic below.
3. We could put it up and take it down easily.
4. We could just pile it and cover it until the next year.
My County started putting plastic snow fence up on its overpasses. The Ministry continued using its old sign boards a few more years and in my travels throughout the Province and beyond, I began to notice other jurisdictions use the fence. We had a small wrinkle that I don’t think was copied everywhere. We make no effort to fence the portion overpass above the wide median.
Ideas come as a result of many factors (availability of materials, a change in conditions, new equipment or research, a push from some outside source) and are massaged by those who have to do the work. This one arose from such a combination.
Here in Eastern Ontario, we started the use of orange plastic snow fence on freeway overpasses, and it spread. We didn’t copy anyone. It was our contribution to the safety of the driving public. We don’t doubt that someone, on their own, elsewhere in the snow belt may also have had the idea. Those things happen, but without prompting, here, it was our idea