How to build a speed detector?

[Jim Thompson]

[ snip]

3) On the fast freeways keep a distance of at least 2 seconds.


<LOL>, I mean, really, <LOL> Maybe at off hours.

I'm aware of the US americans to be absolutely insane on this aspect.
I myself drove in LA at 65 mph with 5m distance, some factor 10 below
the 2 seconds. The uneasy feeling was terrible. You had to concentrate
during every heartbeat. No looking around, no thinking ahead. No
day-dreaming.

I'll stick with our 2 seconds.

My rule is you have to see at least some pavement between you and the
car ahead

And where were you that they were only doing 65?

Around here it's more likely to be 85.

And the cops have timed some drivers on the new section of Loop 101 at
110.

Considering the speedlimit is 55 Mph or so, we felt pretty outlawish
when doing 65. But that was in California.
In Utah, you feel outlawish when doing 56 Mph, one mile more than
usual.
And you're in Texas you said. Interesting, drivers paradise then.

Rene

Naaah! I'm in Phoenix, Fields is in Texass ;-)

...Jim Thompson

 

[Jim Thompson]

On Wed, 02 Jun 2004 23:17:46 +0200, the renowned Rene Tschaggelar
[snip]

I'll stick with our 2 seconds.

Rene

You just were not used to it. Once you get used to it, you can whip
along any of those freeways while shaving, talking on the phone,
reading the paper, blow-drying your hair, cleaning your guns,
whatever. Didn't you look at the other drivers? No white knuckles.
Once you get out of the congested areas the traffic tends to go a lot
faster than your observed 65mph (only 100km/h).

Best regards,
Spehro Pefhany

I once observed a gal curling her eyelashes while driving down
Scottsdale Road... a street with lots of stops and starts

And you're right, NEVER make eye contact!

...Jim Thompson

 

[mike]

On Wed, 02 Jun 2004 22:32:18 +0200, the renowned Rene Tschaggelar
[snip]

3) On the fast freeways keep a distance of at least 2 seconds.

<LOL>, I mean, really, <LOL> Maybe at off hours.

Why LOL?

Because (around here, Toronto, and in many North American cities with
big spread-out expressway systems) if you leave anything like that
amount of space, either someone will pull into it sideways from other
lanes, or, if there is room, the guy or gal behind you will (sometimes
angrily) pass you and move into it ahead of you (so that you don't let
in an endless stream of cars, slowing down that lane).

Best regards,
Spehro Pefhany

It's pretty amazing.
I try to drive at a constant speed and let the distance to the next
car change as the traffic ahead does the stop/go/accordian thing.
The guy behind just can't stand going at a constant speed and feels
compelled to pass me, usually with a hand gesture, so he too can do the
accordian thing. I think cars must have a secret brainwave killer;
probably put in there by people who make brake linings.
mike

--
Return address is VALID.
Bunch of stuff For Sale and Wanted at the link below.
Toshiba & Compaq LiIon Batteries, Test Equipment
Yaesu FTV901R Transverter, 30pS pulser
Tektronix Concept Books, spot welding head...
http://www.geocities.com/SiliconValley/Monitor/4710/

 

[Jon Elson]

If the accidents involve you running into the car in front this often,
then an electronic solution is not for you. You have some fundamental
problem with spacial awareness that should make you consider giving up
driving... you are dangerous. Sell your car, and use the money -plus
what you would have spent on this project - on taxis.

I had an MR2 some years ago, and had a number of accidents and near
accidents
with it, all where I was suddenly faced with a slow-moving car right in
front
of me. I couldn't figure it out, I had a great driving record before
that car.
Was I having too much fun driving a neat car?

Well, after totalling it out (got a nice settlement from the insurance,
at least)
and going back to a good driving record, it slowly dawned on me what had
been happenning. Other people just didn't SEE that car! I don't know if it
was the color (kind of a darker silver) or the low profile, but people were
pulling out of side streets and driveways, RIGHT in front of me.

Other than wrecking a rental on the San Francisco area freeways at the
height of rush
hour, while I was trying to read a map so I didn't pass my exit AGAIN,
I haven't had a wreck in over 15 years, since getting rid of the MR2.

Jon

 

[Jim Backus]

My rule is you have to see at least some pavement between you and the
car ahead

And where were you that they were only doing 65?

Around here it's more likely to be 85.

And the cops have timed some drivers on the new section of Loop 101 at
110.

...Jim Thompson

The preferred method of avoiding damage and accidents is to keep a
safe distance - the rule of thumb in the UK is one car length for
every 10 mph.

The alternative is to remember that the damage and injuries are not
caused by the speed but by the decelleration. Therefore it can be
argued that it is safer to follow as close as you dare. You'll often
hit the vehicle in front but the differential speed will be small
because the vehicle in front will not have slowed much when you hit
it. But please don't take this as a recommendation - just an
observation of Newton's laws of motion ))


--

 

[Ken Smith]

My rule is you have to see at least some pavement between you and the
car ahead

If you drive with your bumber touching the car in front, when they apply
their brakes, they just slow you down too. There can't be any difference
in speed so there isn't a crash.

[...]

And the cops have timed some drivers on the new section of Loop 101 at
110.

Check the parking lot exit at quiting time. Its out onto a city street
but some of the cars have a red shift.

 

[Tim Auton]

If you drive with your bumber touching the car in front, when they apply
their brakes, they just slow you down too. There can't be any difference
in speed so there isn't a crash.

True, but you might end up pushing the car in front into the kid its
braking to avoid.


Tim

 

[Tim Auton]

Spehro Pefhany wrote:

[not keeping a safe distance between cars on the motorway]

It's pretty amazing.
I try to drive at a constant speed and let the distance to the next
car change as the traffic ahead does the stop/go/accordian thing.

The stop/go/accordian thing is the problem with following too closely
(other than the risk of crashing). If you need to use your brakes on
the motorway (freeway, autobahn...) you're doing it wrong. Traffic
flows more slowly with random braking and acceleration. Admittedly if
everyone else is doing it wrong it's hard to do it right

The M25 (London's orbital motorway - no, it's not in space!) has
variable speed limits in places. You can get more cars through at
50mph or 60mph than you can at 70mph, because they can be closer
together. It works remarkably well.

The guy behind just can't stand going at a constant speed and feels
compelled to pass me, usually with a hand gesture, so he too can do the
accordian thing. I think cars must have a secret brainwave killer;
probably put in there by people who make brake linings.

I think people just don't get it. The police should have unmarked cars
which randomly brake as hard as possible to help educate people.
Hitting the back of one should cost you a ticket, plus the inevitable
hike in your insurance premiums.


Tim

 

[JeffM]

Safe following distance is 2 sec

I was taught it was 2s at 30mph and 4s at 70mph.
Tim Auton

This is *minimum* following distance, based on reaction time only.
It assumes that the driver has normal reflexes and eyesight,
is not distracted, and that he will be braking at a rate
at least as great as the guy ahead who just jammed on his brakes.

For the OP I would say this optimism is unwarranted.

 

[martin griffith]

I'm aware of the US americans to be absolutely insane on this aspect.
I myself drove in LA at 65 mph with 5m distance, some factor 10 below
the 2 seconds. The uneasy feeling was terrible. You had to concentrate
during every heartbeat. No looking around, no thinking ahead. No
day-dreaming.

I'll stick with our 2 seconds.

Rene

You should try living (and driving )in Spain!!!!!!!
The locals here, drive so close to the rear of my campervan, I cant
see them in the wing mirrors.

I now use the mirrors to look for shadows on the road! This doesnt
work at high noon though, Must get a CCTV system fitted




martin

Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.

 

[Rene Tschaggelar]

Jim Thompson wrote:
[snip]
And you're in Texas you said. Interesting, drivers paradise then.

Naaah! I'm in Phoenix, Fields is in Texass ;-)

...Jim Thompson

Silly me, it was even visible in you signature. It was close
to midnight. At least the two states are bordering to each
other, I recall.

Rene

 

[Fred Bloggs]

You just were not used to it. Once you get used to it, you can whip
along any of those freeways while shaving, talking on the phone,
reading the paper, blow-drying your hair, cleaning your guns,
whatever. Didn't you look at the other drivers? No white knuckles.
Once you get out of the congested areas the traffic tends to go a lot
faster than your observed 65mph (only 100km/h).

Best regards,
Spehro Pefhany

That's just dumb- the damned engine is not going to last any amount of
mileage driving at those high speeds. I will never push mine above 3000
RPM- and as for the sub-normal IQ who want to make driving an adventure-
just take another route. It was just last week when I was returning home
during a very heavy rainstorm, the road drainage was very bad, and I was
already planing at 45MPH- so that was my top speed- and I was being
passed at relative velocities of what had to be 30MPH by a bunch of
clueless SUV drivers. Well- at least two them are now ex-members of the
living- 15 minutes down the road, two of them had broad sided some 0MPH
trees, which don't like to move for anything, roofs crushed, lifeless
corpses inside. This whole thing with high speed driving is nothing but
usury of the most worthless morons in existence. High speed equates
exponential increase in material consumption , road and parts wear-and
fuel consumption- a national display of stupidity and proud of it they
are- pathetic.

 

[Spehro Pefhany]

Silly me, it was even visible in you signature. It was close
to midnight. At least the two states are bordering to each
other, I recall.

Rene

Nope. New Mexico is between.

http://www.cdc.noaa.gov/USclimate/states.fast.html

Best regards,
Spehro Pefhany

 

[Tim Auton]

That's just dumb- the damned engine is not going to last any amount of
mileage driving at those high speeds. I will never push mine above 3000
RPM- and as for the sub-normal IQ who want to make driving an adventure-
just take another route.

[snip tale of dead, stupid SUV drivers]

This whole thing with high speed driving is nothing but
usury of the most worthless morons in existence. High speed equates
exponential increase in material consumption , road and parts wear-and
fuel consumption- a national display of stupidity and proud of it they
are- pathetic.

I like driving to be an adventure and I certainly not of sub-normal
IQ. If I want to drive fast I will. I won't endanger other road users
while doing so though. It's perfectly possible to drive fast and be
safe, you just have to pick *where* you drive fast. Busy roads in
rainstorms are not the place and SUVs are not the tool.

I guess you'd be upset if I passed you with a clear lane between us on
a dry, empty, straight road if you were doing 65mph and I was doing
120.


Tim

 

[Tim Auton]

I certainly not of sub-normal IQ.

Oh, the irony...


Tim

 

[Spehro Pefhany]

You should try living (and driving )in Spain!!!!!!!
The locals here, drive so close to the rear of my campervan, I cant
see them in the wing mirrors.

I now use the mirrors to look for shadows on the road! This doesnt
work at high noon though, Must get a CCTV system fitted

Heheh. Sounds like driving in Italy. As long as you ignore the lines
on the road (like everyone else) and NEVER look in the rear view
mirror (unless you want to be terrified) you are fine. When in Rome...

Best regards,
Spehro Pefhany

 

[Spehro Pefhany]

This is *minimum* following distance, based on reaction time only.
It assumes that the driver has normal reflexes and eyesight,
is not distracted, and that he will be braking at a rate
at least as great as the guy ahead who just jammed on his brakes.

For the OP I would say this optimism is unwarranted.

The OP is from Malaysia, no? They have an excellent public transit,
bus and train system- very inexpensive, efficient and safe. And lots
of inexpensive taxis in Kuala Lumpur and other cities such as Malacca,
Georgetown, Penang, Johore Bahru, Kuching, Sibu. That may be his best
solution. A very pleasant country, including especially Borneo, BTW,
highly underrated.

Best regards,
Spehro Pefhany

 

[Fred Bloggs]

I like driving to be an adventure and I certainly not of sub-normal
IQ.

Maybe castration would make the accelerations less of a thrill- have you
considered that?

 

[Tim Auton]

Maybe castration would make the accelerations less of a thrill- have you
considered that?

I'm perfectly capable of keeping my desire for acceleration under
control as it is, but thanks for the suggestion.

Perhaps a spliff and a blow job would help to chill you out a bit -
have you considered that?


Tim

 

[Jan Panteltje]

Maybe castration would make the accelerations less of a thrill- have you
considered that?

What are you carying on about?
200km/h is nothing....
A kid can do that (I did).
hehe
In that time it was still legal here...
Germany autobahn has some nice fast driving too.
Dunno what the max is, perhaps 300km/h?
(Over to them).
JP