02-11-2019, 07:01 PM
(02-11-2019, 03:50 PM)danbrotherston Wrote: If a vehicle drives outside of the roadway area, it's going to be dangerous for someone. Some traffic engineering manuals in the US have the concept of a "clear zone" where out of control vehicles should be able to safely fly through without risk of serious collision, these "clear zones" usually include sidewalks...because that's how traffic engineering is.
This is actually perfectly sensible for freeways, but as far as I’m concerned it constitutes criminally negligent malpractice in urban areas (“streets” rather than “roads”).
https://youtu.be/P9BUyWVg1xI
Quote:That being said, I think the "danger" is greatly exaggerated. As you yourself pointed out, the bollards they would use would not stop a car. They might cause some damage, but a car leaving the roadway in an uncontrolled manner will simply flatten a metal bollard, without harming the vehicle occupants--this is the case with the bollards in Kitchener, which are routinely hit. Other risks far outweigh the danger of hitting the bollard, for example, a vehicle hitting a flex bollard will not change direction, one hitting a metal bollard could be deflected slightly. A driver hitting a metal bollard on the side is possibly more likely to swerve in a dangerous way (although I'm not convinced on that one).
One difference is that a metal bollard cannot be ignored — even if the car won’t be stopped outright, it will be at least slightly damaged, and it would be clear to everyone that intentionally driving into one would be an act of vandalism. Whereas this is not true of the flex bollards. So the metal ones will stop all deliberate incursions into the sidewalk, leaving only accidental high-speed / large vehicles, whereas flex bollards will leave the real dregs of unashamedly irresponsible drivers still able to perpetrate their offenses.