A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto newsgroups » Driving
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

"Cover your break"?



 
 
Thread Tools Display Modes
  #1  
Old February 4th 05, 08:33 AM
Magnulus
external usenet poster
 
Posts: n/a
Default "Cover your break"?

I've heard this advice alot. My question is, why cover your break at
an intersection- what use does it do?

Suppose I enter an intersection with a green light at 30 mph (following
the usually defensive driving advice to slow down a bit), and I just happen
to see that pickup comming at me at 40 mph, running the red light. What
good will slamming on the brake do? Will my car really stop that fast?
Wouldn't it be better to slam on the accelerator (assuming my car could
accelerate that quickly?)

What's the proper "defensive driving" technique in that situation that
would make covering ones brake a good thing? I suppose- maybe, if you
stopped fast enough the pickup might catch you on the front end instead of
the midsection of the car. Any clues?


Ads
  #2  
Old February 4th 05, 11:07 AM
Robert F Merrill
external usenet poster
 
Posts: n/a
Default

Magnulus wrote:

> I've heard this advice alot. My question is, why cover your break at
> an intersection- what use does it do?
>
> Suppose I enter an intersection with a green light at 30 mph (following
> the usually defensive driving advice to slow down a bit), and I just
> happen
> to see that pickup comming at me at 40 mph, running the red light. What
> good will slamming on the brake do? Will my car really stop that fast?
> Wouldn't it be better to slam on the accelerator (assuming my car could
> accelerate that quickly?)
>
> What's the proper "defensive driving" technique in that situation that
> would make covering ones brake a good thing? I suppose- maybe, if you
> stopped fast enough the pickup might catch you on the front end instead of
> the midsection of the car. Any clues?


Slowing down makes it easier to turn (i.e. swerve out of someone's way)
without spinning out/throwing your passengers into the doors.
  #3  
Old February 4th 05, 08:42 PM
Arif Khokar
external usenet poster
 
Posts: n/a
Default

Magnulus wrote:

> I've heard this advice alot. My question is, why cover your break at
> an intersection- what use does it do?


What's a break?
  #4  
Old February 4th 05, 09:14 PM
Garth Almgren
external usenet poster
 
Posts: n/a
Default

On 2/4/2005 11:42 AM, Arif Khokar wrote:

> Magnulus wrote:
>
>> I've heard this advice alot. My question is, why cover your
>> break at
>> an intersection- what use does it do?

>
>
> What's a break?


That thing you're suppose to cover at an intersection. Duh.


--
~/Garth |"I believe that it is better to tell the truth than a lie.
Almgren | I believe it is better to be free than to be a slave.
******* | And I believe it is better to know than to be ignorant."
for secure mail info) --H.L. Mencken (1880-1956)
  #5  
Old February 4th 05, 09:34 PM
external usenet poster
 
Posts: n/a
Default

A writer asks if they should "cover the brake" when approaching an
intersection.

Sounds like a bad intersection design. If you don't have visibility to
see a vehicle approaching on the cross road to make your go/no go
decision then the posted speed is too high. Or your scan pattern is
faulty.

Green, to me, means the driver has to "clear the intersection". The
driver has to visually sweep the approaching roads to avoid crashes.

A signal implies visibility of cross traffic. Otherwise the
intersection should be controlled by two way or four way stop signs.

Or better yet, a roundabout or a flyover.

Speeds are set at the 85th percentile of observed speeds. Drivers
adjust speeds for congestion, but not for sight stopping distance. Or
consent relative bearing crashes.

Yellow signs versus white signs.

This intersection sounds like it needs some engineering corrections.

To me, covering your brake means to put your foot on the brake and even
actuate it to the point of lighting the stop lamp, but not actually
forcing the pads onto the rotors. This saves maybe 200 milliseconds,
about one half car length at 40 MPH.

If you are trying to control your car to the nearest half car length at
30 MPH, you are way over the control limit of steering or braking. You
are very likely to induce steering oscillation and overturn your car if
you try to steer fast enough to miss the approaching car. At thirty
MPH, you should allow a cushion of at least three car lengths. That
includes the approaches from the sides.

Give yourself more cushion. One car length for each ten MPH up to 30
MPH then two car lengths for each ten MPH over 30 MPH.

Approach speeds are nearly equal in your example. Thirty and forty MPH.
Angle of constant relative bearing, about 50 degrees for the slower car
and 40 degrees for the faster car. The driver of the slower car MIGHT
notice the faster car if he moves his head and eyes. Neither driver
will see the other car if the cars remain on a constant relative
bearing and the drivers don't move their head and eyes. Or if there are
shrubs, trees or buildings in the line of sight.

If you are covering the brake in anticipation of the light turning red,
you need some practice on solving the dilemma zone.

There is a segment of road on the approach to a signal where you can
either proceed before the light turns red or stop safely, even of you
still have some yellow.

At some point in the approach to the signal, you need enough confidence
to stop looking at the light. Not because you know you are going to
make the green, but to scan for other vehicles. If you concentrate on
the light all the way to the cross bar, you will not see other traffic.

For most intersections, the solid lane divider gives a visual clue. If
you are at the speed limit to about 5 MPH below and the light is still
green when you reach the solid line, your car will enter the
intersection before the light turns red. Don't speed up, don't slow
down. Look for cross traffic.

Next time you are a passenger going through that intersection, notice
how much of the cross road you can see. Can you see the cross road
through the side windows? Or is anything beyond the A pillar blocked by
shrubs or signs?

  #6  
Old February 4th 05, 09:37 PM
Bill the second
external usenet poster
 
Posts: n/a
Default


> wrote in message
oups.com...
> Speeds are set at the 85th percentile of observed speeds.


They should be, but aren't always.


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
rec.autos.makers.chrysler FAQ, Part 1/6 Dr. David Zatz Chrysler 10 January 2nd 05 06:15 AM
rec.autos.makers.chrysler FAQ, Part 1/6 Dr. David Zatz Chrysler 10 December 18th 04 06:15 AM
rec.autos.makers.chrysler FAQ, Part 1/6 Dr. David Zatz Chrysler 10 December 2nd 04 06:19 AM
rec.autos.makers.chrysler FAQ, Part 1/6 Dr. David Zatz Chrysler 10 November 1st 04 06:24 AM
rec.autos.makers.chrysler FAQ, Part 1/6 Dr. David Zatz Chrysler 10 October 16th 04 05:28 AM


All times are GMT +1. The time now is 08:49 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AutoBanter.
The comments are property of their posters.