Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Dashes for safety.

  1. Jul 24, 2010 #1
    Following to close while driving is a deadly mistake. Two seconds, I think we all deserve them, plus it is the law. For those of you who don't know how to tell, at sixty five miles per hour it works out to be about one of the dash lines that separate the lanes per half second between vehicles in the same lane.

    I try to give my wife one second, two dash lines, between her and I while riding our motorcycles, of course I am not following directly behind her, we ride staggered in our lane. Two dash lines, one second, may seem like a large area to people within a cage of steel, but on a bike it is not. Please think about it, even "if" you and your cage can fit between us, please do not.

    While you may think I am waving because of how friendly I am, be assured the two fingers I am waving are to remind you of the two second rule and please use it, after all the life you save may be mine.

    This is a letter I wrote to the editor of my local paper and I don't know whether to laugh or cry but the most common response I have received to date is "you can't use the dash lines you need a stationary landmark". :rofl: :cry:
  2. jcsd
  3. Jul 24, 2010 #2


    User Avatar
    Gold Member

    My personal rule is that I use three seconds while following a regular vehicle or four seconds if it's a bike in front of me. 33" Trail Handler tires on an El Camino present a ridiculous amount of rotational inertia that just curls its lip up at the concept of 'brakes'. I need that extra second to downshift.
  4. Jul 24, 2010 #3
    I hate people who tailgate me. It's counter-productive. Do they think I'm going to speed up? I'll go the maximum speed limit, but when they get on my tail like that, it becomes minimum speed limit time.
  5. Jul 24, 2010 #4
    This is one my my biggest pet peeves while driving. I can't stand tail gaters. When I have one behind me I always take my foot off the gas and coast even to the point of going only 40 in a 65. As soon as they get out from behind me I speed up again and try to make sure to give them the national gesture of disapproval so they realize I was slowing because of them.

    When I am in the car with friends who tail gate I get on their case about it. Most of my family tail gate too but none of them would take kindly to me telling them how to drive.
  6. Jul 24, 2010 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    One of my brothers got his first ticket for tailgating...a cop! When he was asked about it, he said, "Well, the cop was driving too slow!" Yep, he was a bit...cheeky.
  7. Jul 24, 2010 #6


    User Avatar
    Gold Member

    There was a rather large young lady with vanity plates that used to tailgate me on my way to work at least once a week. She followed so close that I couldn't see her front license plate, and as I glanced to the rear-view, I'd see her eating, talking on her cell, applying makeup etc. It was ridiculous. When I rode my bike to work instead of taking a car or truck, I would pull over into the break-down lane so I could get her in front of me. She would speed up and tailgate the next vehicle in front of her. It was pathetic.
  8. Jul 24, 2010 #7


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    You're one of those guys who slows everyone down in their lane, and then when someone tries to pass you speed up to stop it! A pox on you demon!
  9. Jul 24, 2010 #8
    Lol. I slow down only when I am being tail gated. And I only speed back up to normal speed when the tailgater changes lanes. ;-)
    But seriously, I have no idea what the person in front of me might do and if they suddenly break for some reason, and I have some idiot riding my tail, someone is going to get rearended. Slowing down gets plenty of distance between me and the person ahead of me just in case so I and the jack*** both have plenty of breaking room.
  10. Jul 24, 2010 #9


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Actually, that's just what I was taught in driver's ed (taken...wow, 30 years ago :surprised!). When you're being tailgated, increase the following distance, for just the reason you stated.
  11. Jul 24, 2010 #10
    Ever had someone tailgate you up to a green light? If that light turns yellow and I have to slow down fast, they're going to hit me. They're either trying to intimidate me into going through the light or they're just too stupid to realize the danger in what they're doing, and can't even think one step ahead (the light turning yellow).
    People need to start getting some jail time for this crap. They're allowed to roam the streets acting like this, then when they cause a disaster that kills a family, everyone is shocked. It's not shocking. I'm surprised it doesn't happen more often.
    Cars need to be treated like any other weapon. If you risk people's lives with a gun, you don't just get a ticket and get to keep your gun.
  12. Jul 24, 2010 #11
    The worst tailgaters are the ones who do it even though the lanes all around you are completely free. They could easily have gotten into another lane and passed you safely. Instead, they ride right on your bumper for no reason whatsoever.
  13. Jul 24, 2010 #12
    I never took drivers ed. Just seems like common sense to me.

    I remember that thread. It was the first one where I saw you and Dave get into it, and with me popping in here and there. I always remember good arguments. ;-)

    I have not had that happen to me so much though. I do not slow down terribly before a stop and avoid the tailgaters as much as possible.
  14. Jul 25, 2010 #13


    User Avatar
    Gold Member

    I couldn't agree more. Oddly enough, given the vast array of unbelievable morons with whom I've been forced to share the road for the past 40 years, I was rear-ended only once. That was about 6 years ago by a very sweet young lady (18-20) who was not exactly at fault. It was here in the town where I live, -30°, and the street was glare ice. The area is a 50 km/h zone, which is the maximum within town limits, but we were both doing a more prudent 20 or so due to road conditions. Also, she was maintaining a decent 4 second separation. The light went orange as I was approaching the intersection. Had I been going the speed limit, in good conditions, it would have happened without my being able to stop. As it was, I couldn't have made it through before it went red. So I downshifted to first, tapped the binders, and came to a reasonably acceptable stop. The poor girl behind me had no chance. Her vehicle blatantly refused to do more than slow down slightly. (Anti-lock brakes might have saved her, but she didn't have them.) Anyhow, she ploughed into me at a breathtaking 15 km/h. I barely noticed, but she was so distraught that I damned near cried out of sympathy for her. Her concern wasn't for her vehicle or her driving record; she was worried that she had caused me physical or vehicular damage, and that I might be mad at her. She was, in fact, the only victim of the incident. Her car went straight under the ***-end of mine, without even touching the bumper, and my skid plate crushed her hood down into the engine compartment. My car showed absolutely no evidence of the collision aside from a small shiny streak where some surface rust got scraped off of the skid plate. Her vehicle was still operational, and she drove the half dozen or so blocks home, but I'm sure that the body repairs ran to well over $1,000.
    Okay, I have more to say regarding the general topic, but I'll hold off for a while and just post this as-is.
  15. Jul 25, 2010 #14


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    I guess that they think that the dashboard is a stationary landmark. :tongue:
    I responded to a post on a another forum once from someone who was complaining about driving on the freeway and having the car in front of them using their windshield washer. He was whining about how inconsiderate it was for that person to spray their freshly washed car.

    I wrote in my post that I will sometimes purposely do this when someone is tailgating me on the freeway and I asked if perhaps he was tailgating. For some reason, he never responded. :rolleyes: There were quite a few who loved that suggestion though...
  16. Jul 25, 2010 #15


    User Avatar
    Gold Member

    My high-school buddy deliberately set the washer nozzles on his Datsun 510 to fire over the roof rather that onto the windshield for that exact same reason. Filling the reservois with ink instead of washer fluid merely added injury to insult. :biggrin:
  17. Jul 25, 2010 #16


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    Why am I not surprised? :rofl:
  18. Jul 25, 2010 #17
    I try not to slow down fast before a stop. Sometimes, however, the light will turn yellow and I'll think I can make it at first, but then I realize I'm too far away, then I think it's too late to stop but I end up stopping anyway. It's that little argument in my head that causes those fast stops at a light. It doesn't happen often.
    The primary time I'm worried about getting rear-ended is when I'm going down one of those on-ramps where you're going down in a circle and at an incline. If you have to yield for other cars, the person behind you may smack into you. I've seen that happen a lot. They're not looking ahead, they're looking behind them, speeding up to try to make it into traffic without realizing you stopped ahead of them because you were waiting for an opening.
  19. Jul 25, 2010 #18
    Tailgating is what you get for not hauling *** in the passing lanes. If you want to loiter do it near the shoulder. This is also the law.

    The 2~3 seconds worth of distance between cars is completely impractical in most any situation, just like the 50~150 yards rule between starting to signal and actually beginning to change lanes.

    What is practical and proper is to pay attention to the vehicle in front of the vehicle in front of yours so you don't have to react to its driver's reaction. Not leave football fields of chasm to the vehicle in front counting the dashes while inviting cars in adjacent lanes to switch.

    And this is why window tint should be outlawed and why land yachts and light trucks are a nuisance.

    If most people had any sense & decency there'd hardly be a need for law or enforcement.
  20. Jul 25, 2010 #19
    So it's what you get for not breaking the law in the passing lane? So to avoid breaking the law, you need to break the law? That makes a lot of sense.
    And it's not the law everywhere. Funny thing, laws change depending on where you are.
    Only because people will fill that gap, causing you to have to slow down even more, creating more spaces for people to fill the gap.
    Not always possible. If it's a UPS truck in front of you, you can't see in front of them. And it doesn't even have to be a truck, some people have tinted windows so dark, you can't see through them to see what's in front of them.
    I don't mind a slight tint, but when they have a black car and I can't tell where the metal ends and the window begins, it's obviously way too dark.
  21. Jul 25, 2010 #20
    1) I generally break the speed limit in the passing lane, and I still get tailgated. I guess I'm not passing people "fast enough." If your idea of the law is correct, it is illegal to drive in the left lane at any speed. If you go the speed limit or below, you're not yielding to traffic. If you drive above the speed limit, you're passing.

    I don't feel comfortable with the law saying it's always illegal to drive in the left lane, no matter what.

    Furthermore, as I alluded to in my previous post, some tailgaters will do it even in the middle lane, when the passing lane is completely free.

    Lastly, even if I decided to go 10 mph under the speed limit in the left lane, tailgating is still not excused. It's a danger not only to yourself, but everybody else nearby.

    2) The 2-3 second rule is almost always practical. It's only impractical during the transition period between "free flowing" traffic and "stop and go" traffic.

    3) 2-3 seconds does not leave "football fields" of distance. 60 mph is 88 feet per second. In 3 seconds that's 264 feet, or less than one football field.

    4) You say looking a few cars ahead is "practical," but then you give examples of how it is impractical. Good job.
  22. Jul 25, 2010 #21
    I don't remember exactly but I think the law advises that, at all times, you keep as near to the right as possible, traffic permitting.

    Failing to do so is probably not a misdemeanour. But how are you breaking the law by keeping to the right?

    This, unfortunately is the pervasive and prevailing mentality:

    Hey, I'm doing the speed limit! Nobody should be going faster than me anyways. It's ok to be a pleb and hold up the fast/passing lanes, make them overtake me on the right, endangering everyone.

    Yeah, because such a gap is impractical. Three seconds at highway speed is an enormous distance.

    Yes. But you can overtake them on the left hand side because the driver is respecting the law and keeping to the right.

    That's why tinted windows should be outlawed or opacity limits properly enforced. Tinted windows is the first of many clear cut clues the car belongs to a douchebag.


    The law says to keep as far to the right as possible at all times. In Germany they actually bother to enforce this with fines and license suspensions. It makes a world of difference in civilising the driving population. They also enforce yielding to on ramps.

    Just as it is driving etiquette to allow someone slower to finish their overtake manoeuvre without harassing them by flashing your lights and tailgating them, it is also driving etiquette not to loiter when passing.

    It's all about decency and common courtesy. Just like doing the zipper is when the road narrows by one or more lanes. Too bad they give out licenses like cupcakes these days.

    You probably don't need to be in the passing/fast lanes in the first place.

    It's not illegal. If it is, it's not enforced. I remember the law encourages/advises towards keeping as far to the right as possible at all times.

    I wouldn't know. I keep my eyes on the road ahead. Unless I'm planning on changing lanes.

    You need to be able to stop faster than the car in front. If they're licensed to drive, the person behind should be able to do that while you're checking your mirror. Unless you drive a land yacht or have tainted windows. But then land yachts don't slow down or turn very well.

    How is leaving twice or more the stopping distance to the car in front ever practical?

    83 metres is a lot of distance. In the dry I can stop completely inside of 42 metres from 100 km/h.

    I try and overtake vehicles I can't see through. I can't stand being behind them.

    Also, it is practical. Furthermore, it's considered good practice.

    You are hanging on the few exceptions to dismiss the rule while the 2~3 seconds rule is almost always impractical.
  23. Jul 25, 2010 #22


    User Avatar
    Gold Member

    No offense, Sony, but I hope to hell that you leave your wheels at home and travel by bus if you ever visit Canada. I sure don't want you anywhere near a road that I might be on.
  24. Jul 25, 2010 #23
    You're breaking the law by exceeding the speed limit in the left lane. The speed limit is the speed limit regardless of which lane you're in.
    If I'm going the speed limit in the left lane, I don't MAKE people do anything. If they're driving dangerously, that's their fault, not mine. And if they're driving dangerously, then THEY'RE endangering people.
    You sound like those people who blame the woman for getting raped. She shouldn't have been so pretty to MAKE the person rape her.
    And what makes passing someone on the right dangerous and passing on the left not dangerous? That makes no sense.
    That's like saying skateboarding with your left foot in front is not dangerous, but skateboarding with your right foot in front IS dangerous. What's the difference?
    That is except for when you want to speed? You're criticizing people for breaking the "stay right" law because they're interfering with people who break the speed limit law. You're adamant about one law and then turn around and condone breaking another law.
    As much as you wanted that to make you sound like a good driver, it did the opposite. You should know what's going on around you while driving, not JUST what's directly in front of you. But I don't believe for a second that you never glance at the mirror, or see giant headlights right on your tail unless you're changing lanes.
  25. Jul 25, 2010 #24
    Then you're a bad driver.

    Reaction time. If you're checking your mirrors when the person in front of you slams on their brakes, you won't be hitting your brakes immediately. Additionally, even if you are staring straight ahead, it takes time for your brain to notice that you need to stop, it takes time for that signal to reach your foot, it takes time for you to move your foot over to the brake and depress it. THAT'S why you need more than the stopping distance.
  26. Jul 25, 2010 #25


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The drive under the speed limit law and the pass in the left lane law are independent. It's not 'the left lane is for passing or driving the speed limit.

    Also, Sony you really just discredited yourself as a decent driver
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook