Straight Dope Staff Report on Mythbusters

[Turek]

Woot! A SD sighting on Mythbusters. In the episode about driving a car on a washboard road, they show Grant searching the web for what causes washboard roads, and then clicking on the link to this mailbag column.

[jimbeam]

Yeah, I saw it too. Their conclusion was to drive faster on rougher roads. The following myth was driving while talking on a cell phone vs. DUI. They said it was more dangerous to DWT driving while talking. :O

[Eleusis]

Originally Posted by jimbeam

Yeah, I saw it too. Their conclusion was to drive faster on rougher roads. The following myth was driving while talking on a cell phone vs. DUI. They said it was more dangerous to DWT driving while talking. :O

You sure about that?

I only watched with one eye but I could have sworn it was the opposite.

They thought it would be smoother, or the myth said so, but the slower they went, the less water spilled from their wine glasses.

[jimbeam]

Yeah I'm sure. If you recall, they took some angle iron and built a run/road (if you will) a washboard type replica and retested the myth because the first one was inconclusive. The second test showed that on the washboard type roads it was smoother the faster you traveled. Which was the myth they were testing. The first test was on a rough road with dips and turns. The test didn't really apply to the myth they were supposed to bust.
The jest of it was:
At a high rate of speed the tires stayed airborn longer and as a result they hit less bumps in the road.

[C K Dexter Haven]

The Mythbusters' problem is, as always, that they do only one test. If the "true" answer was 60% of A and 40% of B, they'd never know that. Even if the "true" answer was A 95% of the time, their results could have been the one oddball. Unless they run a test several dozen times and note the different results, I'm loathe to buy in blindly.

[Dunderman]

Originally Posted by C K Dexter Haven

The Mythbusters' problem is, as always, that they do only one test. If the "true" answer was 60% of A and 40% of B, they'd never know that. Even if the "true" answer was A 95% of the time, their results could have been the one oddball. Unless they run a test several dozen times and note the different results, I'm loathe to buy in blindly.

They're kinda like Cecil in that respect.

God, I wish we got Mythbusters here.

[jimbeam]

The thing is..when I was an undergrad I lived down a road exactly like they're describing. Friggin washboard, didn't matter what the county did either. It'd be a washboard within days after running the maintainer down it. It was an old river bottom road and rough as a cobb.

I guarantee you faster is smoother than slower. It's rough on the shocks but easier on the body and driver. I'd say about 40-45 was a good speed. Too fast and safety is an issue. Too slow and it'd just beat you to death.

[DSYoungEsq]

I grew up in the Mojave Desert. The valley I lived in had a lot of unpaved and unimproved (no oil added) dirt roads. You learn quickly the optimum speed to take such roads for the car you are driving to lessen the effect of the washboard.

If you are willing to take the time, driving VERY slowly is always best. We're talking under 20 mph here. At slow enough speeds, your shocks can handle the bumps without transmitting too much jolting to the seats. But you get VERY tired of driving 10 MPH across 5 miles of desert.

The speed to take the road to ride on top of the washboard varies from car to car (not surprisingly). I used to drive an old '71 Valiant around alot, and had to use an older '69 Chevy wagon (the big one) when I couldn't. There was a difference of at least 5 mph between the two for smoothness.

The one trouble with the "drive fast and smooth it out" method is that, while it works fine for the washboard, it plays hell with you when you hit a REAL bump, which tends to happen with depressing regularity on dirt roads.

[Lightnin']

You know, I disagree with their explanation of washboard.

Granted, some washboard is natural, and forms exactly the way they stated. However, in my experience, washboard is also intentionally made. Up at my family farm, the county will come through and grade the lane- and the washboard is extremely bad immediately afterwards. That washboard will gradually fade away, and the road will smooth out. I've seen the same thing up here in Oregon- dirt roads which don't have much traffic tend to have the worst washboard, and it's the length of the road, as opposed to in spots, which wouldn't be explained by their version of vehicle-induced washboard.

I've always assumed they washboarded the road to cut down on wear and tear of the dirt road itself. Maybe it helps with erosion? Or maybe they're just trying to keep people from driving like damnfools down the road?

[DSYoungEsq]

No offense, but I have a hard job believing that the county or state can put in a "washboard" type surface, let alone would. I'd love to see what you think they use to accomplish that task...

[jimbeam]

Originally Posted by DSYoungEsq

No offense, but I have a hard job believing that the county or state can put in a "washboard" type surface, let alone would. I'd love to see what you think they use to accomplish that task...

He's right, I've seen them do it myself. But it wasn't done on purpose. It was because the lazy bastards were in a hurry and just ran through the area trying to do a two week job in two days. The maintainer was just bouncing along and recutting the same pattern. They should've adjusted the angle on the blade, slowed way the fuck down to a crawl and recut the road making several passes. Instead they just run up one side and down the other.
My old man used to work for the county. (Not the one I'm talking about though.)

Old joke... what is green, has four wheels and sleeps three. A county pickup truck.

[Jake]

I don't see why they went to all the trouble with the angle iron and welding. Just find a patch of dirt road and run a Cat D-9 over it a few times and you'll get the same washboard effect. Them things is HEAVY!

[C K Dexter Haven]

Originally Posted by Originally Posted by C K Dexter Haven

The Mythbusters' problem is, as always, that they do only one test.

Originally Posted by PriceGuy

They're kinda like Cecil in that respect.

Hey, c'mon. Cecil occasionally does a one-off experiment to see what's what, but that's pretty rare. Most of the time, there's massive statistical support for what he's saying. MYTHBUSTERS runs single experiments; Cecil provides knowledge.

[Dunderman]

Originally Posted by C K Dexter Haven

Hey, c'mon. Cecil occasionally does a one-off experiment to see what's what, but that's pretty rare. Most of the time, there's massive statistical support for what he's saying. MYTHBUSTERS runs single experiments; Cecil provides knowledge.

I was half-joking. Cecil did once refer to himself as (paraphrased) the guy famous for making broad statements on the basis of one-off experiments in the back yard.

[DSYoungEsq]

Originally Posted by jimbeam

He's right, I've seen them do it myself. But it wasn't done on purpose. It was because the lazy bastards were in a hurry and just ran through the area trying to do a two week job in two days. The maintainer was just bouncing along and recutting the same pattern. They should've adjusted the angle on the blade, slowed way the fuck down to a crawl and recut the road making several passes. Instead they just run up one side and down the other.
My old man used to work for the county. (Not the one I'm talking about though.)

Old joke... what is green, has four wheels and sleeps three. A county pickup truck.

Well THAT I could believe easily enough. Probably does nothing more than scrape whatever loose sand has accumulated off without actually affecting the packed dirt...

[jimbeam]

It may be part that but from my observation it seemed like the front wheels which are way out in front of the blade are simply bouncing on the rough road making the blade bounce as well.
I've seen them actually do it right once when I lived there but that involved cutting the road down slowly and deep then bringing in more road bed material and laying it out with a blade several times.
BTW it didn't last very long either.