New speed limits proposed for South Africa

Archer

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Jan 7, 2010
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Yeah, changing the speed limits will make about zero difference to the accident/fatality rates in this country.

The only way to make a dent in that problem is effective and visible policing, which they're incapable of doing.
Only partially correct
Safe roads start with city planning which rolls down into road infrastructure design that actively encourages safe driving vs fast driving
 

Sinbad

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Jun 5, 2006
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100 km/h will mean that my car will never change into top gear and this will increase my fuel consumption. This was probably proposed by a 30% civil servant who do not have a driver's license but knows someone who drives a 1998 Tazz.

Such a plan will probably cause more accidents on highways.
It will drop your fuel consumption by about 20 percent.
 

Sepeng

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Dec 12, 2011
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Only partially correct
Safe roads start with city planning which rolls down into road infrastructure design that actively encourages safe driving vs fast driving
I seem to recall some stat, one of them Scandinavian countries, basically every single kilometre of their road network has lighting. With lights that work.
Now look, all the lights in the world can't make up for just bad and reckless driving but still, imagine that.
I agree with the visible policing and consequences though. I was in a police car once and the number of people you see buckling up, putting down cell phones as you drive past is amazing.
 

Lupus

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Apr 25, 2006
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Thanks for bringing that up. My fuel consumption is a lot lower at 100km/h than at 120k/h regardless if I drive in 4th or 5th gear.

The energy required to travel faster is proportional to the square of the velocity.
So for example if it takes 40kW of power to propel a vehicle at 100km/h then it will require approximately 57.6kW to propel a vehicle at 120km/h. That's a 44% increase in power to travel 20% faster.

With regards to the difference in speed there is another factor to take into account. The energy which needs to be dissipated in an accident is also proportional to the square of the velocity. This makes a massive difference in the survivability of the crash.
If two cars each traveling at 140km/h have a head on collision the total effective closure rate is 280km/h. A very scary thought. At 100km/h the closure rate will be 200km/h.
The energy which needs to be dissipated in the head on crash at 140km/h is nearly double the amount at 100km/h.
Pilots also make a mental note of this when thinking about forced landings. A small reduction in speed when landing can make a huge difference in the energy carried into a crash situation.
Except that the two cars colliding at 140km/h would be like a car colliding into a wall at 140km/h not 280km/h

 

RedViking

Nord of the South
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Feb 23, 2012
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Thanks for bringing that up. My fuel consumption is a lot lower at 100km/h than at 120k/h regardless if I drive in 4th or 5th gear.

The energy required to travel faster is proportional to the square of the velocity.
So for example if it takes 40kW of power to propel a vehicle at 100km/h then it will require approximately 57.6kW to propel a vehicle at 120km/h. That's a 44% increase in power to travel 20% faster.

With regards to the difference in speed there is another factor to take into account. The energy which needs to be dissipated in an accident is also proportional to the square of the velocity. This makes a massive difference in the survivability of the crash.
If two cars each traveling at 140km/h have a head on collision the total effective closure rate is 280km/h. A very scary thought. At 100km/h the closure rate will be 200km/h.
The energy which needs to be dissipated in the head on crash at 140km/h is nearly double the amount at 100km/h.
Pilots also make a mental note of this when thinking about forced landings. A small reduction in speed when landing can make a huge difference in the energy carried into a crash situation.
Good grief, I should have worked harder on that matric.
 

ChuckMeFarley

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Jun 18, 2011
Messages
402
Please no, people already hug all the lanes, and drive like 20-30km/h in urban areas, not to mention that where I live there is almost a new speed bump every week. People are complaining about these speed bumps, due to there being so many, but who motivated it? I understand speed bumps around dense areas like schools, crèches, etc, but to have like two within 25-50m continuingly is absurd. The city actually started to remove some speed bumps some time ago.
My local shop around the corner is literally 1km away, I pass over 8 speed bumps one way. The route passes around a local high school.
 

Dan C

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Nov 21, 2005
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Except that the two cars colliding at 140km/h would be like a car colliding into a wall at 140km/h not 280km/h

I dare you to try it and tell us.
 

ToxicBunny

Oi! Leave me out of this...
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Apr 8, 2006
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Only partially correct
Safe roads start with city planning which rolls down into road infrastructure design that actively encourages safe driving vs fast driving

As a holistic solution I totally agree with you, but even to make a dent in the shyte behaviour we have on our roads they just need to have effective and visible policing and enforcement of the rules. Do that for 6 months to a year and the general change in behaviour on our roads would be remarkable.
 

BeerIsNotGood...

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Aug 27, 2015
Messages
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We are ready for the autobahns in SA :p

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Roadkill?
 

notayoba

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Feb 19, 2010
Messages
1,166
As a holistic solution I totally agree with you, but even to make a dent in the shyte behaviour we have on our roads they just need to have effective and visible policing and enforcement of the rules. Do that for 6 months to a year and the general change in behaviour on our roads would be remarkable.
I reckon cameras with people that monitor moving violations, with semi permanent roadblocks that get notified by the camera operators who to pull over.

If you start arresting people coming over blind rises while drunk and overtaking illegally it might start making a dent in accidents. It seems to be the provincial sport in the Eastern Cape. In my mind that's bordering on attempted murder/murder. It goes way beyond going a little over the speed limit.

Moving violations (cutting people off, dangerous overtaking, overtaking in the yellow lane, driving 60km/h on a freeway etc. ) also cause huge frustration to other motorists, and they then take out those frustrations on others, and the cycle continues.
 

RedViking

Nord of the South
Joined
Feb 23, 2012
Messages
48,556
The reality is that South Africans do not have respect for each other and in general drivers are extremely selfish and arrogant. No matter what they change it to, our reckless culture of no care or concern for one another will over rule it anyways. Our roads will never be safe. Never.
 

Stonemason

Senior Member
Joined
Mar 13, 2017
Messages
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What's wrong with your car? Why can't you choose a higher gear?
I do not know when last you bought a new car but you should know that most higher end cars these days are automatic and have more than 5 gears. My car only selects top gear (9th) at about 107 km/h and then the revs are below 1500 rpm.
It will drop your fuel consumption by about 20 percent.
No, it will not because my particular car's speed and engine revolutions cannot be optimally matched for economy at 100 km/h
 
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