Re: The two second rule needs further discussion Quote:
Originally Posted by NomadSK So you made me scratch my head. Your analogy is correct as long as you are comparing it with the fixed object with zero velocity. But the 2-second rule or whatever second rule is with respect to the relative speed of the vehicle being followed. It’s a thumb rule at any relative speed (technically which should be zero) have the tailing and following car.
Only problem I can see is, if car A comes to an abrupt halt (0 speed in 0m distance) by colliding with a rigid concrete wall, then your logic of 2 second being insufficient holds good. That’s not an ideal scenario though.
Generally it’s a rule in normal driving conditions, adverse weather conditions will require more time frame (gap) for safe driving.
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Well for defensive driving you need to prepare not for the "normal" but abnormal. Here are some scenarios that you might want to consider
1. The car you are following has a tyre burst.
2. For some reason there is a visibility problem, a curve where an idiot has parked or the is a wild animal or the holy cow etc
3. In any scenario where the car in front has "superior braking" (technically infinite). This "braking" can be "achieved" by rear ending another car, bursting ones tyre or any of the numerous "techniques" that we Indian drivers are well versed with.
I think you really need to think of the car in front as a something that can metamorphosis into a brick wall at any point in time. If that is your model of the car in front what I said is the inescapable conclusion. Quote:
Originally Posted by tilt Er... I believe you're conflating distance with time. The two seconds is time and is not supposed to be calculated into a distance. |
No I am not conflating distance with time. If you are following the 2 sec rule (say rather strictly) then at any point of time the distance between you and the car in front is proportional to your speed (speed * 2 ). I am objecting to this rule. Modified 2 sec rule
Here is how I think two sec rule should be implemented in practice.
1. Set a threshold speed say 40 kmph below which you are comfortable with using the 2-sec rule. I will call this the 2-sec threshold.
2. For every 40 kmph additional speed add 2-sec to your the "following time". This can be summarize as follows
2.1 Till you hit 40 kmph follow 2 sec rule
2.2 Between 40 to 80 follow 4 sec rule. Or say 40-60 (3sec) and 60-80 (4sec)
2.3 Between 80 to 120 follow 8 sec rule
2.4 Beyond 120, you should not be driving on any roads in India
In practice you might want to have a different threshold. May be due to slippery roads or you are driving a heavy vehicle or you are growing old and do not want to trust your reflexes too much (case in point me). Then you may choose a lower 2-sec threshold. Say you choose 20kmph as your 2sec threshold. Then for every 20 kmph increase your "following time" by 2 secs. As with the usual two sec rule, you will need to adjust your following time depending on the hazard. In our case it amounts to lowering the 2-sec threshold.
Last edited by electric_eel : 5th February 2024 at 11:34.
Reason: grammar
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