Wikipedia:Reference desk/Archives/Miscellaneous/2014 January 25

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January 25

Safe Driving Technique

Suppose one is driving a car fitted with a traditional manual transmission on a snowy/icy winter highway. Is it safer to drive at more or less a constant speed on a higher gear or lower gear (say, 4th vs. 5th)? On a higher gear, there is less output torque at the wheels, so it should spin out less easily right? But on a lower gear, you have more engine braking to handle emergencies. Does this make a difference if the car is Front wheel drive vs. rear wheel drive vs. all wheel drive? Thanks Acceptable (talk) 15:55, 25 January 2014 (UTC)

Advice from the British RAC Limited recovery service (the majority of cars in the UK have manual transmission); How to drive in snow says; "In these conditions, it's all about keeping the revs down.... drivers going up a hill should try to stay in the highest gear possible, rather than being tempted to drop down into first. But when going downhill drivers should go down gears." Alansplodge (talk) 18:24, 25 January 2014 (UTC)

The American Automobile Association (AAA) has Winter Driving Tips (see: "Tips for driving in the snow"). In addition to advice above, they emphasize maintaining inertia (momentum); and accelerate / decelerate slowly. Also "Know your brakes", and apply "threshold breaking". At the bottom there are 2 PDF downloads that might be helpful. For specifics on how to regain control of your car under varying scenarios, The Weather Channel has good advice here: Driving in Snow and Ice. As far as type of vehicle is concerned, all-wheel drive is obviously best, followed by front-wheel drive. Optional advantages would be having traction control and anti-lock brakes. ~I hope this helps, ~E:71.20.250.51 (talk) 05:07, 26 January 2014 (UTC)

In an emergency, you don't use the engine brake (unless if the emergency is that the brakes fail). Sjö (talk) 09:31, 26 January 2014 (UTC)

What is an engine brake? Alansplodge (talk) 13:02, 26 January 2014 (UTC)

See engine braking. Dismas|^(talk) 13:16, 26 January 2014 (UTC)

Aha! I was expecting it to be some fancy gizmo that they have on American cars (some lorries do have a compression release engine brake). The British Institute of Advanced Motorists recommends that in snow, you ought to "Drive so that you do not rely on your brakes to be able to stop - on an icy surface they simply may not do that for you!".[1] That implies at least an element of engine braking; but I agree that for general driving, it's a bad idea. Alansplodge (talk) 15:11, 26 January 2014 (UTC)

... unless you generally drive down steep hills, when relying just on brake pads can cause them to overheat. I've seen cars with smoke pouring from their brakes because they didn't know about engine braking. (I occasionally use it for corners, too, when I need the lower gear afterwards.) Dbfirs 17:11, 26 January 2014 (UTC)

There are other ways to stop without using your brakes. With a manual transmission, or an automatic in neutral, it will slowly coast to a stop on level ground, and quickly stop when going uphill. The uphill part is particularly applicable when leaving a recessed highway. If you get it right, by the time you leave the exit ramp you will be almost stopped. Of course, in most cases, some use of the brakes is still required, but hopefully not so much as to cause the car to spin out in snow and ice. StuRat (talk) 17:13, 26 January 2014 (UTC)

You've just reminded me of the time when I used those techniques to drive a hundred miles, including city roads with traffic lights, motorway, and country roads, without ever touching my brakes (because I knew they were leaking and might fail). I sometimes repeat the exercise for shorter distances, reserving my (now good) brakes for emergencies, or for when another driver does something I didn't anticipate. (Safety warning: it is dangerous and illegal to drive with faulty brakes!) Dbfirs 17:48, 26 January 2014 (UTC)

It's generally a good idea to use engine braking, and it's taught in driver's education in Sweden to increase mileage. The downside is that if you don't sometimes brake hard, rust will build up on the brake discs, especially at the rear wheels. This might mean that you have to replace them earlier. As for engine braking in in snow, the reason you should drive slow is that the friction on ice and snow is so low that the wheels might skid. Engine braking won't help against that, the opposite in fact as it's harder to apply just the right amount of braking and anti-lock brakes don't work with the engine brake . (Also, using only two wheels to brake will increase the risk of the wheels losing traction. ) Sjö (talk) 21:11, 26 January 2014 (UTC)

Incidentally, one will fail the "Emergency Stop" section of the UK Driving Test if one does not use the engine to assist deceleration. Although it's been a good many years since I took it. :) Tevildo (talk) 22:29, 26 January 2014 (UTC)

Engine breaking is a vital technique to learn - but with ABS, and on ice/snow, it doesn't do much that just using the brakes will do. The advantage in doing it is because most people aren't sufficiently gentle with the brakes to do a good job and letting the engine slow you down provides for a more gentle deceleration. That said, it's perfectly possible to induce a skid with engine braking...so it's no panacea. But using engine braking routinely as an alternative to the actual brakes is a bad idea...not that it doesn't work...it most definitely does...and it's also a hell of a lot of fun! The problem is that a new clutch costs a heck of a lot more than new brake pads...so when choosing which surface you intend to wear down, you might want to go with the ones that are designed for that purpose!

In the end, all good driving (in the snow and ice, when it's wet, on gravel or even in the dry) is about balancing the amount of acceleration you need to achieve some manouver against the amount of grip your tires are providing. (With "acceleration", in this context being taken in the sense of the way the word is used in Physics - meaning speeding up, slowing down, turning or some combination of those things). Driving in a dead straight line at 90mph works just fine in ice and snow...so long as you don't need to go around any corners, or slow down because the guy in front is going 30mph! So it's all about balancing the demands you INTEND to place on the vehicle in terms of speed and direction changes against the grip your tires are able to deliver. It's also about driving in such a way that other people can predict what you're going to do so that they too can balance the demands they may have against what their car can do. Leaving a HUGE stopping-distance gap to the car in front is essential - and if there is some idiot behind you who isn't leaving enough space - then pull over and let them get on with it without you! It's perfectly possible to drive fairly fast, and safely in ice and snow - but only if absolutely everyone around you is doing the same. In places where everyone gets lots of practice at it, I don't mind driving in snow and ice at all - you just have to calibrate your brain to the much lower rates at which you can turn, speed up and slow down - and you'll be fine. But here in Texas, where people get to do it maybe once in every ten years (and insist on driving rear-wheel-drive pickup trucks with no weight over the back wheels!)...I stay home if there is even the slightest sprinkle of the stuff! SteveBaker (talk) 16:22, 27 January 2014 (UTC)

A good tip for safe driving in snow is to not do anything sudden, no sudden changes of direction, no sudden changes of speed, and try to avoid doing both (changing direction and speed) at the same time. Anticipate what may happen ahead including that the car might slide, and remember that a slow slide is easier to control than a fast slide, and is likely to cause less damage if you do hit something. Astronaut (talk) 12:16, 27 January 2014 (UTC)

Absolutely! SteveBaker (talk) 16:22, 27 January 2014 (UTC)

I like to summarise this as "minimise the magnitude of any acceleration", which includes changes in speed, direction and the potential violent deceleration of a crash. Equisetum (talk | contributions) 10:34, 28 January 2014 (UTC)

So you advocate the "leaving the car in the driveway" approach to safe driving then?  :-) SteveBaker (talk) 19:50, 28 January 2014 (UTC)

Okay then, if you really want the long version: "mimimise acceleration as much as possible consistent with driving at a reasonable speed for the road conditions", although, as I do not currently possess any motorised vehicle, I do practise an even more extreme version of the "leaving the car in the driveway" approach. Equisetum (talk | contributions) 14:34, 29 January 2014 (UTC)

bents fort

In the descriptions of bents Fort it offers a quote from Ralph Emerson Twittchell about where the Old Bents Fort was located. Somewhere along the Arkansas River between Pueblo and Canon City. I thought it was out by Las Animas Colorado, way east of Pueblo? Which is correct? — Preceding unsigned comment added by 65.129.184.141 (talk) 16:04, 25 January 2014 (UTC)

Well, the statement that it was between Pueblo and Canon City is presented, as you say, in the context of a quotation from a 1909 book and not as a statement by Wikipedia itself. The location of Bent's Old Fort National Historic Site in Otero County, between Los Animas and La Junta, is clearly correct as the site of the current National Historic Landmark and reconstruction of the fort, and it seems to be the site of the original fort. Perhaps Twitchell was mistaken about the location. Deor (talk) 17:29, 25 January 2014 (UTC)

Ralph Emerson Twitchell's bio suggests that he would have known the area thoroughly. Is it possible that the description was for Bent's Fort and not Bent's Old Fort? Although I am ignorant of this specific place, I have come across similar dual-location names. If there is a Bent's Old Fort one might assume there was/is a Bent's [New] Fort (which might have been temporary?). ~Just a thought, ~E:71.20.250.51 (talk) 05:32, 26 January 2014 (UTC)

Good call. PBS - New Perspectives on the West - William Bent (1809-1869) says "...Bent's Fort, a massive adobe outpost on the north bank of the Arkansas River in present-day Colorado, which William Bent constructed in 1833...". The article continues; "In 1857, Bent constructed a new outpost thirty-eight miles downstream from his old fort, gathered a group of settlers and created the first permanent American colony in Colorado". So it seems that there are (or were) two Bent's Forts. Alansplodge (talk) 12:35, 26 January 2014 (UTC)

Some more information about "Bent's New Fort" is in this article which says; "In 1853 Bent built a new stone fort east of the old one, in what is now known as Amity in Prowers County." Another fort was built by the army "a mile west of Bent's New Fort in 1860", which came to be called Fort Lyon and is now a "correctional facility" (a prison perhaps?). Alansplodge (talk) 17:54, 26 January 2014 (UTC)

And finally, everything that you wanted to know about Bent's New Fort is here. Alansplodge (talk) 18:03, 26 January 2014 (UTC)

In the article, one must read between the lines to deduce the facts about two separate entities; the article certainly needs improvement to clarify this apparent ambiguity. For example, the quote by Twitchell. So... which knowledgeable, friendly and helpful Wikipedia volunteer feels up to the challenge?    ~:71.20.250.51 (talk) 20:06, 26 January 2014 (UTC)

The problem is that none of these locations are "between the present cities of Pueblo and Canyon City" as the Twitchell quotation states. Bent's New Fort was, as has been mentioned, east of the old fort, whereas a site between Pueblo and Cañon City would be a considerable distance (60–100 miles) to the west, as the OP pointed out. Deor (talk) 22:14, 26 January 2014 (UTC)