Safe Overtaking

[Pisces69]

I seriously think there was something wrong with his brakes...

 

Or another way to look at it is that if he needs such a long distance to stop, he should not be traveling at 100km/h

 

 

U need 1 car length fr every 10kmh to safely stop so 10 car lengths fr 100kmh is correct.

 

U double that to 2 car lengths fr every 10kmh on wet/slippery roads or on dark roads at night.

 

I use e 2 seconds rule as i find it easier to judge my safe following distance to e car in front.

 

 

[Pisces69]

obviously the problem lies with the user, not the car

if a car cannot come to a complete stop with a 5 car length buffer at only 100km/h then it will be a major road hazard and we'll have forte accidents everywhere already

but we don't do we?

thus user problem, don't blame the car

 

10 car lengths at 100kmh is e correct distance to stop SAFELY.

 

Safely means also allowing cars behind to stop safely.

 

Very few drivers practise that in SG, thats why we see so many chain collisions on our eways.

 

Many drivers over-estimate their n their cars ablities here.

[Pisces69]

Doesnt seem to have any problem. Cuz after that accident he sent for repair they checked everything and the brakes were ok. Maybe the abs never work properly cuz there was a screeching sound. Like as if the tires locked up intermittently.

 

10 car lengths fr 100kmh is correct to stop safely. Keep to it fr safety.

 

U can follow bumper to bumper if it makes u feel like a race car driver but then again how many of us r really as good as those race-car drivers.

 

Only after u crash into e front cars back wil u realise how quickly u crash into e front car but by then its too late.

[Pisces69]

The car was quite new. Less than 10000km. Cuz he just bought it at that time. Maybe the stock tires not good. But after that when he sold the car the new buyer also did not notice anything wrong with the brakes. At 100km/h with 5 car lengths u only have 0.9 seconds to react and step on the brakes if not u will hit the car in front. If I did not remember wrongly the average driver reaction time is around 1.5s?

 

Exactly. Reaction time plus actual stopping distance is much longer than what many think, until its too late.

 

[Pisces69]

Err...sorry but WRONG.

 

It is not braking that matters but reaction time.

 

The average driver takes 1.5 seconds between seeing the brake lights of the car in front, and depressing his own brake (0.75 secs to recognise and decide on action, 0.75 secs to move foot and push brake)

 

At 100 km/h you are travelling at 41.66 m per second [(100 km/h x 1000m per km)/3600 seconds per hour]

 

1.5 x 41.66 in my math = 62.5 m....how many car lengths is that?

 

 

Ive been driving fr abt 30 years n had several near misses n a couple of rear enders too.

 

I can assure u it happens much faster than u can imagine n that is if u r paying full attention on e road.

 

What about those drivers who dont put 100% concentration on e road.

[Pisces69]

not sure about the calculation but 100km/h speed with 62.5m gap sounds very wide to me.... btw, at 100km/h, it should be 27.77m/s....

 

 

Many drivers feel 10 car-lengths at 100kmh is too big.

 

Maybe thats why i see so many chain-collisions on our eways.

[Pisces69]

and just to add on, only kuku driver will purely base on the front car brake signal to react..... should be as front as possible (2, 3 or even 4 cars or more if within view..) to anticipate the needs to release acc or brake...

 

Yes when we drive, we sud b looking 3-4 cars in front to anticipate an emergency.

 

[Nzy]

Jammed brakes usually brake lights light-up, so can see. If brake lights do not light-up more critical? (encountered 2 buses, 2 cars, like that)

 

I guess thats why nowadays car manufacturers program the hazard light to turn on when u jam brakes. Even my hyundai also like that. If I jam brakes the hazard light will turn on till I release the brakes.

[Speedsun]

Just buy Volvo S60, auto calculate of the required stopping distance for driver. There is no need to argue about 2 seconds rule or how many cars length needed.

[Sdf5725]

Doesnt seem to have any problem. Cuz after that accident he sent for repair they checked everything and the brakes were ok. Maybe the abs never work properly cuz there was a screeching sound. Like as if the tires locked up intermittently.

 

driver problem then. thik it is better he/she drive slower next time. dont take lane 1 for sure.

[Nzy]

driver problem then. thik it is better he/she drive slower next time. dont take lane 1 for sure.

 

Yup. Thats his problem. He always tailgating. His reaction was already very fast but the gap was too small.

[Jchuacl]

Wait a minute, even if there is a problem with ABS, it does not affect braking distance.

 

My take is

 

- Poor tyres

- Did not step on brake hard enough

- the road is slippery, ie some oil on the surface.

 

There you go. Even you suspect that there was a problem with the ABS

 

[Phluvcat]

ermmm...I think 1.5s total reaction time is a tad too slow.

 

assuming full awareness of road situation, time taken to react should preferably be in the region of 0.1 to 0.5s. time taken to shift the foot to brake should be 0.1 or less (because this naturally follows in a subconcious manner). total reaction time should be no more than 0.6s, or else based on 1.5s and 100kph, one might have "shot thru" 2 to 4 cars in front (assuming cars in front also take some time to come to a stop), confirm up lorry.

 

even based on 0.3s, car would have moved by about 12m, not yet counting stopping distance.

 

total reaction time either prevents collision in the first place or able to lessen the impact, it also boils down to the vehicles in front come to a complete stop faster or in a shorter distance than you.

 

more often than not in a chain collision, the upfront cars would have come to a complete stop much earlier than the last car, so reaction time and stopping distance becomes even more crucial.

 

actually, if you think 0.1s reaction and shifting time is unlikely to be achieved, just try your stop watch, can be achieved easily, in fact less than 0.1s comfortably if your stopwatch shows hundredths of a second, but most do not. but if you still think 0.1s is daunting, then dun tailgate, keep a safe distance.

 

try using peripheral vision and anticipate during driving, cuts down total reaction time considerably.

 

simple mathematics and for me, hogging is a lesser evil as it is natural for a driver to reaction fast to front than back. of course hogging is not encouraged and hogger should give way safely.

[Nzy]

ermmm...I think 1.5s total reaction time is a tad too slow.

 

assuming full awareness of road situation, time taken to react should preferably be in the region of 0.1 to 0.5s. time taken to shift the foot to brake should be 0.1 or less (because this naturally follows in a subconcious manner). total reaction time should be no more than 0.6s, or else based on 1.5s and 100kph, one might have "shot thru" 2 to 4 cars in front (assuming cars in front also take some time to come to a stop), confirm up lorry.

 

even based on 0.3s, car would have moved by about 12m, not yet counting stopping distance.

 

total reaction time either prevents collision in the first place or able to lessen the impact, it also boils down to the vehicles in front come to a complete stop faster or in a shorter distance than you.

 

more often than not in a chain collision, the upfront cars would have come to a complete stop much earlier than the last car, so reaction time and stopping distance becomes even more crucial.

 

actually, if you think 0.1s reaction and shifting time is unlikely to be achieved, just try your stop watch, can be achieved easily, in fact less than 0.1s comfortably if your stopwatch shows hundredths of a second, but most do not. but if you still think 0.1s is daunting, then dun tailgate, keep a safe distance.

 

try using peripheral vision and anticipate during driving, cuts down total reaction time considerably.

 

simple mathematics and for me, hogging is a lesser evil as it is natural for a driver to reaction fast to front than back. of course hogging is not encouraged and hogger should give way safely.

 

Human reaction time is around 0.5s is correct. But thats only the time for u to decide to brake u also need to add in the time taken for ur leg to move to the brake pedal and the time for u to depress the pedal fully. Add all up and the average driver reaction time is around 1.5s.

 

[Nzy]

Wait a minute, even if there is a problem with ABS, it does not affect braking distance.

 

My take is

 

- Poor tyres

- Did not step on brake hard enough

- the road is slippery, ie some oil on the surface.

 

He definitely stepped on the brakes hard enough cuz the abs kicked in already. Cannot be road slippery cuz the other guy could stop faster. If the road slippery then the guy infront should also have a longer stopping distance. I guess the only thing that could cause the problem is either the stock tires of forte are lousy or not the distance was too short. And the tires were still quite new cuz the car's mileage was less than 10000km at that time.

Edited October 24, 2010 by Nzy

[Good-Carbuyer]

Car A is cab?

 

when i do what Car B did, most cabs will flash high beams.

Perhaps you enjoy driving happily more than getting into accidents. Many/most cab drivers lack sleep, so mental fatigue make them less alert in driving. So they flashed high beam at you because they about to fall asleep?

[Thedream]

U need 1 car length fr every 10kmh to safely stop so 10 car lengths fr 100kmh is correct.

 

U double that to 2 car lengths fr every 10kmh on wet/slippery roads or on dark roads at night.

 

I use e 2 seconds rule as i find it easier to judge my safe following distance to e car in front.

 

Bro, can I suggest that if you're not confident of keeping less than 10 car lengths when traveling at 100km/h, to keep to lanes 2 or 3. I'm not suggesting who's right or wrong, but you will notice that practically no one keeps 10 car lengths' distance on lane 1. You will be frustrating people behind who would like you to keep up with the flow of traffic.

[Thedream]

Wait a minute, even if there is a problem with ABS, it does not affect braking distance.

 

My take is

 

- Poor tyres

- Did not step on brake hard enough

- the road is slippery, ie some oil on the surface.

 

It does. ABS prevents locking of the wheels. This is where the wheels are not moving but the car is sliding front. At those speeds, cars can stop in shorter distances if the wheels are decelerating rather than locked.