A Politician With Some Common Sense - Speed Limits

[k31th]

So do I... I enjoy talking to somebody who can actually logically counter an argument. Look forward to your response. (sorry if I'm wasting your Friday night haha)

[arronm]

The problem is speed limits have remained the same since we drove EH holdens with drum brakes. I now drive a VF with so many safety features its crazy. SO in some areas speed limits could be easily raised.

Freeway could easily be 120 in Perth

[Kimberley Scott]

Double all speed limits force better cars and drivers.

Then double them again.

[Never had any say Panda]

Okay...... watching while writing..

Lets get started..

First off I dont disagree with a lot of what he says. He raises alot of fair points especially his statement about tightly regulated and highlt policed environments.. I disagree with it strangling the system. However I do agree that a moments indiscretion can get you caught and fined. Letme clarify the strangling point.

Most people are away how choked busy freeways are... would increasing the speed to 120kmh on a busy freeway improve congestion? f*ck no. Why? Because the exit ramps are goddamn 60kmh local streets quite often with traffic signals, roundabouts or a stop sign at the end of them. Those intersections queue back to the freeways/highway very fast. You're getting people to an accident hotspot faster. Speed limits take into account very large scale traffic models which allow you to model how an entire network operates when parameters are changed.

Next..

Its not the 85th percentile rule. No rules. It is more of a coroners court defendable speed you can design a road to. Ill try not to use name calling but he is very uneducated in what he is talking about here. 85th centile speeds are measured with a posted limit in place. Say the road is 80kmh we do an operating speedassessment where we measure what speed every vehicle is doing and determine what the 85th of that is. please note that the 85th is usually measured at a single point (straight) of a predetermined sectionnof road. Then we do the operating speed model where you use tge 85th and you calculate based on all the horizontal curves in the road and their superelevation (crossfall) whether vehicles are overdriving or underdriving horizontal curves based on the grip coefficients needed to safely steer around the bend. Now standards change and alot of roads are goat tracks built in the early 1900's that have just continuously gotten upgraded so some very poor geometry has been built into our roads.

The next thing the 85th is used for is to calculate how far in advance of the vehicle a driver should be able to see an object 200mm higher than the road surface and stop completely (lane locked) or safely manoeuvre around it. This is the criteria that gets expensive. Howver we are bound by standard to use rates of decel that havent been revised since 1995. But research has recently been done that suggests modern drivers have worse perception/reaction than drivers back in the 80's so the distances level out.

If you need to cut down a natural rise so drivers can see over it.. you cost mkre money. The deeper you cut the more likely you are to hit rock.. that sh*t is expensive to remove..

85th speed is purely a design criteria and roads are designed so that people can travel the 85th safely. If you increase the speed ljmit to the 85th we need to design for the 95th and spend more money because people will always think they can go faster.

End post 1.. only 2 mins into the first video

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[Rab]

[arronm]

That must work well. Post the speed limit at 80 and then see what speed limit 85% of drivers travel at. Gee I will have to call Einstein on that one.

85 percent of the time it works everytime............................

Edited 06/02/15 12:10 PM by arronm

[Never had any say Panda]

Lets talk about around the world vs. Australia. Now I agree that more research can go into this. Australia has a very unique road network so 'what works in the USA' doesnt always work here. Im not saying it cant be considered in some areas but lets talk european road standards. A class euro roads (freeways) are not supposed to connect to class C or D roads (local roads). In Australia we f*cking join dirt roads at T intersections to 4 lane freeways.

This could be changed.. but this is something that needs to change in standards now, but we won't see any real difference for 30-50 years.

Our road network just got assessed in qld for a 'speed limit overhaul'. 50 links were identified. Of the 50 engineers onky saw fit to increase the speed of 2.

50 more sections are due to be assessed soon.

Next video.

This dude makes sense so far. He just showed a 6 lane road at 50kmh. If speeds don't match engineering I agree its incorrect. However if the road is a constrained 6 lane (reduced lane widths etc) its a different situation.

I thunk alot of what he says makes sense. Road speeds need to match engineering but in Australia most (please note I said most) of our speed limits are at the limits of the engineering. I know quite a few where speed limits are reactive to high crash histories. Myself I do alot of crash analysis and these reactions that alter limits are pointless as the areas I have seen it happen accidents are fatigue related. One section springs to mind though where the speed limit waz reduced to 90 and the accident rate reduced by 40%. Could be argyed that it was just a better couple years since accident rates need a 10 year history to be accurate.

I cant put exact details but I have been involved with a lot of speed limit increases in QLD amd the NT. These roads did not match the engineering for the proposed speeds but they were assumed it was okay as they had such low traffic volumes.

Once yiu start talking roads with 10-50k vehicles a day, Australian roads largely can not safely accomodate higher limits.

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[Never had any say Panda]

That must work well. Post the speed limit at 80 and then see what speed limit 85% of drivers travel at. Gee I will have to call Einstein on that one.

85 percent of the time it works everytime............................

I see where the skepticism comes from, but largely the 85th is greater than the posted speed. One study I did had a maximum vehicle speed of 228kmh in a 90 zone.

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[Rab]

Will play this game.

End of freeway - 70% went right, 30% left - left feed out road was crappy, single lane, gravel sides, no divider, not maintained 15km stretch.

100km/h zone - zero incidents - traffic flowed really well - 5 min travel time max during peak

Improvements happened.

Now it's dual lane, divided, freeway spec tar, break down lane etc

80km zone, clogged, regular speed cameras (only during the off peak when it's not clogged and empty) - 20 min travel time peak is a very good run - rear ender every other week

I accept that times, traffic flow and population spread changes, but why the fsck am I getting pinged for doing 83 now on a Sunday arvo on a totally empty dual carriage way road that has zero pedestrian access in my ABS equipped, traction controlled modern vehicle when it was perfectly fine to drive down at 120km/h (giving the leeway at the time) when it was little more than a goat track a couple of decades ago in my drum braked, radial tired XR ute? And why the fsck is the camera always sitting on the stretch of empty road where not a single accident has ever happened, while 2 streets over there's an intersection that has 3 low speed incidents every week?

["Captain Retard"]

^^^ Errrrrrrr ......because how else would they be able too raise revenue.

It's not enough anymore for them (yes them) to catch and extract money from us for doing the wrong thing in the wrong place!

Now they have to catch us doing the wrong thing in the right place.......if you know what I mean .

I remember my old man telling me how he used to drive to Melbourne down the Hume, open road speed limit (although you had to prove you were going at a safe speed to a copper), some parts were still unsealed , no seatbelts and cars were rugged but borderline dangerous!

Sounds like fun but they did manage to kill themselves in much greater numbers!

But I think we do need to cull the human race a bit