Drafting big rigs saves a minimum of 10 percent range

[David_Cary]

Come on, no restrained driver of a Tesla has ever died so why worry....

But seriously, what percentage of US driving fatalities happen to a sober driver tailgaiting a semi truck. Can't seem to find it but it is very very low - approaching zero. Rear end accidents are rarely fatal. The speed of impact is not usually very high.

I know ask Tracy Morgan.... technically a rear end collision but truck vs car is a very different story and probably not a sober attentive driver following too closely.

Hey - I'm not condoning drafting but someone please find me a reference where 1% or greater of all US fatalities involve the rear ending of a semi truck while sober and paying attention.

One big advantage of autonomous driving is planned tailgating for energy savings. A good collision avoidance system should allow tailgating.

It is true that these threads on every forum always bring out the safety police. 3 seconds --- maybe on a snowy road in Canada but not on crowded areas of the US....

Interested in the Trauma Surgeon reference. Say hello to Jim D - UNC trained if you ever cross paths, he was my first chief. I see you are in a different group. I might hide myself better - lots of Davids in the world....

 

[EdA]

I was with our daughter last week on I80 and a pipeline truck (Frackers!) was going about the same speed as us, (75mph) and we ended up doing the 7 o'clock stalk for about a half mile because of the hills and he sped up a bit after we created the hill. My daughter made a comment on how his one trailer tire looked really tall and skinny. I noticed that it was bouncing on the road. I told her that it could blow, when they bounce like that they make a lot of heat.

Well about two miles later we hit a nice down hill and he really took off, I'd say he was going about 85 or so and 1/8th mile in front of us and it happened! His tire blew. The vaporized blowing that shot 4" chunks of rubber 40' in all directions. We had the pano and all windows wide open and we felt the shock wave. I was directly behind him in the right lane and I killed the cruise and went full regen and headed for the shoulder. My daughter then started crying because the explosion scared her so bad and she thought something happened to our car from the tire exploding when I started to pull over. (We didn't even reach the debris yet). I told her we were fine and I just did that as a precaution because an explosion like that can cause the truck to wreck or he could throw the big chunk of tire.

All I can say is I'm glad it didn't cut loose when we were in the 7 o'clock position or we would be needing some serious body work, possibly some new glass or worse in the hospital from rubber flying through our open windows.

Now that that story is done back to the topic.

That tire explosion would have been horrible in the 7 o'clock position or in some stunt man following distance at 6 o'clock. You never know when something like that is going to happen. Many consider that 7 o'clock position safe. I was just in it because that's where the cruise control put me.

You never know when something like that is going to happen. I see truck tires like that one probably almost monthly, I drive roughly 40k miles per year and most of that is on highways. I have only witnessed 3 big rig blowouts and all of them left me thankful I wasn't super close when it happened. I can't tell you how many passenger blowouts I have seen. (Want nightmares, go to your local walmart and start counting cars with the chords showing.) Plus the chunks of tire shards in the highway that could get kicked up. Bad news.

I used to be an evangelizing hyper miler. (I was getting 48 mpg out of our 98 protege, my wife was getting 33.) I had too many close calls. Including rigs brake checking me and hitting debris in purpose to kick it up at me. I would close in on the draft until all the buffetting was gone. This usually left me about 1-2 car lengths off the rig. Man, what was I thinking. It's just not worth it.

Amazing story. Not sure how you can drive with the windows down and the pano roof open at 75MPH!!!!
And a recovered hyper miler at that

 

[EarlyAdopter]

But seriously, what percentage of US driving fatalities happen to a sober driver tailgaiting a semi truck. Can't seem to find it but it is very very low - approaching zero.

The number of people who die each year rear-ending a semi trailer is, on average, 423.
Underride guards on big rigs often fail in crashes

Rear end accidents are rarely fatal. The speed of impact is not usually very high.

Not true. At just 35 mph they are actually highly likely to be fatal, as the underride guards on most trucks are poor.

The good news is due to petitioning by IIHS, the standards for underride guards have been improved and are getting better, but still put drivers at risk of fatality in offset collisions. Also, the new and improved guards will only be present on new or retrofitted trucks.

 

[Raffy.Roma]

I would like to point out this video.

 

[woof]

I learned 2 seconds when I got My license.

Who even follows that rule anyways.

I learned 2 seconds when I got my license (a long time ago...longer in dog years!). Recently I took a safe driving course (with my newly licensed teen aged son), they emphasized 3 seconds or more...and we did some in car driving exercises that showed how following less than that at 60 MPH was inviting disaster.

Now I follow at 3 seconds or more--no matter what the other's on the road do.

 

[InTheShadows]

I've been counting seconds a lot on the highways lately. In my area during heavy traffic most people are 1.5-2 seconds. I haven't been in the big cities lately to count though I would need someone (or be) riding shot gun to do that. I personally am quite comfortable at 2 seconds, 1.5 has me on edges. There is no way I would do 1 second especially behind a big rig.

Regular traffic seems to be 2-3 seconds.

 

[green1]

I would like to point out this video.

The Tesla is amazing when it comes to safety, but I can guarantee that those A-pillars won't be enough to keep the back of a semi-trailer out of the driver's face. And yes, I have seen those sorts of crashes before.

 

[David_Cary]

I can't believe I poured through some of the data.

1% of all car vs truck accidents where the critical event was coded were due to "following too closely to respond to unexpected actions" of the non-truck vehicle.

There are estimated 423 rear end fatalities - not an average, an estimate. So roughly 1% of all vehicle fatalities.

So 1% of 1%. Or 3-4 deaths per year. Just so we know what we are talking about. Now it certainly may be more than that - but I doubt 10X more.

I imagine someone has done the math but 35 mph pictures are impressive but 35 mph collision speed would be hard to do I think. If you are tailgating at 1 sec at 65 mph and the truck slams on the brakes and you do nothing, what is the impact speed? Might it be as low as 10 mph? 20?

Is it not true, there is a 3/4 second lag time for brake engagement on a semi? Would the 2 sec rule that people apply to cars, really be 1.25 sec for semi's? - since the brake lights have zero lag time.

When something close to 50% of people text while driving....

You do very well to draft a big rig in the next lane. Certainly can get 10% of range. No question, much safer.

 

[InTheShadows]

The Tesla is amazing when it comes to safety, but I can guarantee that those A-pillars won't be enough to keep the back of a semi-trailer out of the driver's face. And yes, I have seen those sorts of crashes before.

I'm not sure if I agree with you there. The A pillers are huge. They are so big that after 18k miles I still complain about having a hard time seeing around them in certain situations.

On another note with opposing traffic at 60mph a rock flew off a big rig and hit my windshield the other day. It left a nice mark about the size of a 50 cent piece. I had never had a stone hit the windshield that that was that large before. I was surprised my windshield didn't shatter. Much lesser rocks have spidered my windshields before.

After we stopped I got out to wipe the lime dust from the rock off the window to see how bad the chip was. To our amazement after we scraped the pulverized rock dust off the windshield with fingernails there was not even a mark on our windshield.

Another amazing Tesla moment.

 

[dhrivnak]

1% of all car vs truck accidents where the critical event was coded were due to "following too closely to respond to unexpected actions" of the non-truck vehicle.

There are estimated 423 rear end fatalities - not an average, an estimate. So roughly 1% of all vehicle fatalities.

So 1% of 1%. Or 3-4 deaths per year. Just so we know what we are talking about. Now it certainly may be more than that - but I doubt 10X more.

Sorry it is actually 100X reread the 3rd sentence 423 deaths due to rear end collisions. 1% of the 45,000 traffic fatalities would be about 450 deaths so the numbers seem to match.

What I do know is 100% of my tickets in the last 25 years (1 ticket) was due to drafting. Not worth the slight savings in range.