Corner Advisory Speeds
Posted: Sun 01 Oct, 2017 11:59 pm
Travelling down south today I went through a 20kmh advisory speed corner on Commonage Road.
This is one of the lowest advisory speeds that I have seen on main WA roads (discounting traffic calming and shared pedestrian precincts). You did not need to slow down to 20kmh to take the corner on a motorcycle.
I understand that advisory speeds are established by a Ball Blank Indication to measure g-forces and relate to car driver comfort rather than limits to adhesion.
It seems ludicrous that most drivers ignore advisory speed limits. They are not enforceable but depending if you drift or squeal your way around a corner you could be a candidate for dangerous driving. Also apparently you void your insurance every time you exceed the advisory speed for a corner.
Some traffic calming has advisory speed limits when you can ride straight through on a motorcycle...does that void your insurance policy even if you stay within the posted speed limit?
It has not been policy to post advisory speed limits on gravel roads as by the time you get to the nominated g force you have lost adhesion. With the progressive sealing of gravel roads the old signs may not be updated leading to surprises mid corner.
There are a few corners in WA that have less margin than you expect as they have poor camber, they tighten or are just badly rated. Other corners have a bump or surface distortion that necessitate lower speed.
Should there be advisory signs just for motor bikes for corners? These would be different on the inside or the outside of a curve and would take into account the length of a curve and changes in camber.
I just think there is too much variation for the current advisory speeds on corners to be much use to motorcycles.
Bozo
This is one of the lowest advisory speeds that I have seen on main WA roads (discounting traffic calming and shared pedestrian precincts). You did not need to slow down to 20kmh to take the corner on a motorcycle.
I understand that advisory speeds are established by a Ball Blank Indication to measure g-forces and relate to car driver comfort rather than limits to adhesion.
It seems ludicrous that most drivers ignore advisory speed limits. They are not enforceable but depending if you drift or squeal your way around a corner you could be a candidate for dangerous driving. Also apparently you void your insurance every time you exceed the advisory speed for a corner.
Some traffic calming has advisory speed limits when you can ride straight through on a motorcycle...does that void your insurance policy even if you stay within the posted speed limit?
It has not been policy to post advisory speed limits on gravel roads as by the time you get to the nominated g force you have lost adhesion. With the progressive sealing of gravel roads the old signs may not be updated leading to surprises mid corner.
There are a few corners in WA that have less margin than you expect as they have poor camber, they tighten or are just badly rated. Other corners have a bump or surface distortion that necessitate lower speed.
Should there be advisory signs just for motor bikes for corners? These would be different on the inside or the outside of a curve and would take into account the length of a curve and changes in camber.
I just think there is too much variation for the current advisory speeds on corners to be much use to motorcycles.
Bozo
