Instead of creating one proximity point with between 100m to 400m radius, can you try creating the proximity points at a point before the sharp bend itself? Make this point on 10m in radius. That way, drivers on other roads will not receive the speed warning. Please refer to my attached gdb for better understanding.
Hi Bro Antyong,
Many thanks for your suggestion, I am a fan of your mapping work.
I did think this over sometime ago and mulled over the placement of trigger waypoints and their radii.
However, I'm not sure if a mere 10m proximity will be effective from the safety perspective. For one thing, once a driver has passed that particular point there won't be any more alerts. He or she may not notice that one and only alert (distraction on the phone, talking to passengers, in-car radio too loud, their mind being elsewhere, etc). "Huh? What was that? What was it saying?"
Therefore a 400m radius means as long as the driver is above 60 km/h within the perimeter the alert will continue to trigger. (I call it nagging
I'm familiar with that stretch and it has claimed many lives before. Given your suggested placed marker, I measured it at 210 meters before the apex of that bend. In a worst-case scenario, at 130km/h the car would reach the apex in exactly five seconds. Putting into account the delay of the Garmin unit giving off the alert plus other overheads like the reflex time of the driver and the effective braking time of the car, that would probably shave off another two seconds off. Too close for comfort, if you will.
At 400 meters, the safety margin is increased to 11 seconds. That should give ample time for the most dare-devil driver to react and stomp on the brakes
. To be frank, I've yet to test that bend myself from both directions so I don't really know if Damansara-bound vehicles will equally receive the trigger.
In the course of learning how to set up custom GPIs, I read that the waypoint has to be placed exactly
on a Garmin recognized road and
you must be on that road itself, otherwise it won't alert you. I'm not too sure about this and I don't travel that much these days.
That's why I need people to actually test this out.