130km/h limit

[burnz]

Originally Posted by Brazen

Well I sent letters to the Minister of Transport, local member, opposition leader and Premier advocating for higher limits on rural roads. I explained the benefits for fatigue, restlessness, inattention, frustration and travel times. What have you slackers done....?

ohh nothing, just getting slacker.

[GasoLane]

Originally Posted by burnz

ohh nothing, just getting slacker.

Yeah. Like me we're all apathetic, but who cares?

[Romulus]

Originally Posted by spvd02

I think the main problem with raising the speed limit so high is our crap roads. On WA roads sometimes you just don't know what's gonna hit you, road surface wise, so I wouldn't like to be doing 130km/h when something pops up on the road that I cannot avoid.

Apparently fuel economy heads South pretty quickly too, when you look at figures higher than 100km/h. So in the interest of safety and fuel economy, I would say 110km/h is just fine. It might feel slow, but it's not.

This is what happens when you travel at the speed limit and collide with a roo. Fortunately it was only a tail strike, thus the damage is negligable.

If I was travelling another 20-30km/h faster I would have avoided the roo
On a serious note though I ignored my own advice about travelling too early or too late during the day in outback WA. I won't second guess myself again.

Fuel economy starts to head south over 150-160km/h.
At 100km/h the ute consumes 9.5l/100km
110km/h - 10.5l/100km
120km/h - 11.5l/100km
130km/h - 12.5l/100km
150km/h - 14.5l/100km

As a comparison my NT Turbo diesel auto Pajero uses:

100km/h - 10l/100km
110km/h - 12l/100km
125km/h - 14.5l/100km
130km/h - 15l/100km

The ute uses less fuel that the Pajero at an speed over 90km/h. Further to that, the ute lopes along at 1650rpm per 100km/h in 6th gear. At 150km/h the engine is ticking along at a mere 2250rpm. 130-140km/h is a very comfortable speed to cruise at on roads which permit such speeds.

[aussie muscle]

i think from the point of view most pollies and roads authorities fear that an increase in speed will result in increased fatalities. You authorise faster speeds and deaths increase by say 5 per year, the media will hold you responsible for all those deaths.

[Romulus]

Originally Posted by Kamshaaft

Of course this is true. Any results otherwise are purely due to other variables i.e. Gearing ratios (which are directly connected to engine rpm, and thus how much fuel you use in one cycle), which sometimes happen to increase efficiency at a certain speed more than the air resistance increases. Holden and Ford tend to gear their newer cars to be most efficient about highway cruising speed. It is important to be aware of this, as You can't thwart physics!

Air resistance on a motor vehicle is about the strongest hinderance to it's progress forwards, and air resistance goes up by the SQUARE.*
You will burn more fuel at 130km/h than 100km/h, even if you had another gear to change up into to sit at the same rpm in both cases (and thus eliminate any effects of varied rpm - which does make a big difference - as anyone who's throttled a gutless 2.0L cylinder just to get it around town and seen the fuel needle plummet on par with a 5.0L cruising can attest to).

The worse you car's Cd (drag coefficient - that is, how aerodynamic it is), or more downforce you have dialed in if you happen to have a racing car, the more you will notice it. In an '84 LTD for example, it will be pretty damn clear.


Related note, Air resistance and gearing are extremely important in having a vehicle efficiently make use of it's limited or limitless power.


*Air resistance is velocity squared, to simplify it by leaving out one part, this means that at 130km/h there is over 60% EXTRA drag than there is at 100km/h.

Agreed. I've noticed bugger all difference in fuel consumption between 80-100km/h and 120-140km/h. Past 140km/h fuel consumption in my ute starts to head north quickly. The gearing in the ute does not afford good fuel economy at speeds below 100km/h, infact the ute uses more fuel at low speeds than moderate speeds. The engine's sweet spot is between 2000-2200rpm in 6th gear, meaning a speed of around 120-125km/h.

I'm in Meekatharra tonight having driven up from Perth today. Data from trip computer:

Average fuel consumption: 12.1l/100km
Average speed: 116km/h
Trip time: 6h16m
Distance travelled: 733.5km

[Franco Cozzo]

http://img64.imageshack.us/img64/7060/imag0036k.jpg

The result of going into a big pothole at about 70km/h, it was at night and Mum didn't see it until it was too late, the tyre is screwed, big bulge in the sidewall.

[paule11]

Originally Posted by Brazen

Well I sent letters to the Minister of Transport, local member, opposition leader and Premier advocating for higher limits on rural roads. I explained the benefits for fatigue, restlessness, inattention, frustration and travel times. What have you slackers done....?

I got a reply from a politician once it was a formn letter that would have been sent to 1000s of people .

The only time they listen is when an election is on

[OZQUAD44]

OK, I haven't read all of the responses in this thread, so I may touch on some items that have already have been covered, but here goes.

Having recently done the Darwin to Alice run, my passenger and I felt that the 130 speed limit was spot on. Given that its in the middle of Banjo-playing country we could have gone faster but there was no need, 130 was plenty fast enough.

The time between destinations was noticeably reduced over the 110 limit where I normally travel. Neither of us felt unduly tired. We had regular driving breaks, and swapped the drive between us. So we were quite alert during our journey. But it did lead me to question wether the heightened speed factor had anything to do with our alertness.

Another thing that we did, was drive to the conditions. At times when the road got a little twisty, there was slower traffic, or the was some other factor that reduced our ability to properly assess the road ahead. We slowed down accordingly. You know just because we could go 130 we didn't always do it. Imagine that, drivers actually being responsible for our own behavior and not a speed camera in sight. How can that possibly be? [Sarcasm]

I'm not for raising the blanket speed limit across Australia, but I'm adamant that there are roads out there that should have higher speed limits. But Alas, no Pollie is ever going to be so dumb as to push that barrow in my lifetime.

I'll give one example where an increase speed limit could actually improve safety. Consider the North bound lanes after Hepburn AVE on the Mitchell freeway in Perth. Every single stinking day the three lane to two lane merging point underneath Hepburn AVE causes a traffic jam to north bound traffic on the (a-hem) "freeway". Now what would happen if the powers that be increased the speed limit north of Hepburn AVE to 110. Logic would suggest that the clearance rate of the traffic from that point on would improve and go some way to address that crappy part of the freeway. Hopefully reduce the need for the tow trucks that regularly frequent that area of an afternoon. The Government are too friggin slack to put a third lane there, so how about a speed limit change then? Don't answer that people.. I know the answer, it goes something like this... Computer says NO!

For years now, traffic authorities had been drumming home the speed kills message. And they have valid reasons. But the problem is, I don't think its actually reducing the number of crashes on our roads. Our governments have got a bee in their bonnet that speed kills, and the horrific crashes to justify their efforts, so speeds aint going up anywhere any time for any reason.

I just wish that authorities would take a more holistic approach to crashes on our roads. I'm tired of the speed message, whilst valid, it isn't the be all and end all of crashes. 80 in 70 zone on an open wide empty straight bit of road is never going to hurt anyone except my wallet. And thats only if the pure horror of exceeding the posted limit by 10 kph is ever discovered by the powers that be. The shame the shame, oh the horrible shame. [Sarcasm]

By focusing on the speed limit as our one and only safety mantra. We inadvertently let off millions of drivers that take extreme risks every single time they drive. Simple things like Tailgating, changing lanes without leaving sufficient room for the car behind you to brake in an emergency, going through green lights without even checking if the cars on the red light have actually stopped, driving through busy intersections without any attention to pedestrians, Maintaining the posted speed limit whether it be rain hail or shine, not taking a break every two hours when long distance driving, opening the car door when parked on the side of the road without first checking the mirrors, The list goes on and on.

What do our pollies bang on about Speed, thats what! One even said that if no-one ever sped then we wouldn't have accidents on our roads..... I think he thought he was being serious.

Drive to the situation. That should be the message! The french add at the start of this thread talks about it. All we talk about in Australia is speed. In my opinion, a valid yet flawed message.

Good luck getting any roads outside of NT up to the 130 speed limit.

[Keepleft]

GT Falcon;
That front-end damage to the Mazda was probably caused by a skippy, distracted by the front fogs being left on in clear conditions:-)

On a more serious note, I am still tending to higher daytime speed limits (120-130km/h), retaining an 80km/h ARR 'rural default', with signposted 100-110km/h night limits - for freeway/rural highways.

Or derestriction overall for latter road category. This is not politically correct, but I don't give a stuff really. (About being too PC).

I've mentioned earlier that NSW (etc) are installing median barrier (plus GATELOCK treatments to the U-Turn bays) to its Commonwealth freeway network with a long term view of upping the 110km/h limit. This link, below, is a Tasmanian 2010 fog crash; note that vehicles have not crossed-over, a good result. Note also the anti-barrier scribe idiots:-)
http://www.themercury.com.au/article...ania-news.html
(+ lack of rear fogs, when really needed).

That French Government 130km/h MP3 tuition link from the first page again:-
http://www2.securiteroutiere.gouv.fr...2006_07_06.mp3

[MO]

^^^ Good luck with that 120/130kph hope it gets up.

[Keepleft]

Originally Posted by MO

^^^ Good luck with that 120/130kph hope it gets up.

I'll drop that MP3 onto Andrew Stoner's (NSW opposition Roads Minister) FB page for his perusal! :-)

[xbgs351]

Originally Posted by Keepleft

On a more serious note, I am still tending to higher daytime speed limits (120-130km/h), retaining an 80km/h ARR 'rural default', with signposted 100-110km/h night limits - for freeway/rural highways.

So most country roads would have an 80 km/h speed limit?

[MO]

Originally Posted by xbgs351

So most country roads would have an 80 km/h speed limit?

I think that is meant towards the lesser country roads say your narrow single strip of bitumen or dirt for the 80kph. The better roads get the 120/130kph daytime and drop to the 100/110kph for night.

[Ben73]

Originally Posted by OZQUAD44

What do our pollies bang on about Speed, thats what! One even said that if no-one ever sped then we wouldn't have accidents on our roads..... I think he thought he was being serious.

That's what they think. And they are trying to convince everyone they are correct.


Ok and to all the people who say that our roads are built for 110...

A road near my house has:
MASSIVE walls on either side.
Grass, shrubs, and a barrier in the middle of the road.
And is smooth, wide, reasonably straight lanes.

But guess what it's posted speed limit is... 90!!!!
WHAT the hell were they thinking? In Germany this road would be classed as a Autobahn because of it's design and quality. but here we have it's limit as 90??? Why????
I cruise on this road at 140km/h in low traffic and it has never felt dangerous to me....unless obviously it was ****ing down with rain or foggy or something.

[MO]

Be careful what you post in regard to speed.

[Ben73]

Yeah sorry about the typo above. I always do the speed limit. I was told by someone the road was good for 140+

[Romulus]

Originally Posted by MO

Be careful what you post in regard to speed.

Agreed, hence no update. I'll go so far as to say an average fuel consumption of 12.9l/100km for the 1580km trip over 2 days impressed the heck out of me.

I can say the 110km/h speed limit is rediculous, bring on open speed limits in outback Australia on roads which can handle such speeds. Most roads up here can cater for speeds in excess of 130km/h.