Why/What is that grating noise you get on the side of the highway?

[NSFL]

The "what you believed as a kid" thread got me thinking about my childhood. As a kid, we used to take a lot of road trips back and forth between Calgary and Regina, and incidentally, still do. But driving on the highway, I noticed that if you got too close to the side of the road, you'd hit a rough patch and it would make a really awful grating sound. Like, the rough patch is "built into the road" right beside the line. I hope you know what I'm talking about.

But yeah, one day, my dad asked me why the road was made like that. My answer: it's so if you're driving at night, and if you kinda doze off, when you start to leave the road, the sound would wake you up. But then my dad was like: what prevents you from turning into oncoming traffic then? And that pretty much messed up my theory.

So to ask CP, why is there that rough patch that makes that awful sound? I'm sure someone here must know. I've tried google, but didn't have much luck.

[ken0042]

I thought it was also to keep you from going into the ditch if you fell asleep.

[Dan02]

I believe you're right, they are in the middle between oncoming lanes in some spots just not most where you have to overtake in the oncoming lanes.

[MarchHare]

Your dad is wrong and you were right all along.

http://en.wikipedia.org/wiki/Rumble_strip

Sometimes they build roads with rumble strips along the centreline to prevent inattentive drivers from crossing over into oncoming traffic, but this is less common than placing them along the shoulder.

[Dion]

It's a reminder to let you know that if you don't correct your steering you will go in the ditch. Can't remeber where but some highways have that stuff in the divided lines to keep drivers from crossing the centre lines.

[MelBridgeman]

It is a god sent when driving in a winter storm on a 2 line highway

[NSFL]

Wow, in your face dad! Thanks for the link MarchHare, I guess google never worked because I didn't know what it was called.

[Dion]

Originally Posted by MelBridgeman

It is a god sent when driving in a winter storm on a 2 line highway

Have driven home from Calgary to High River on ocassions when the snow was coming down quite heavily. You are correct, it is a god sent to have it. Saved from the ditch on those few ocassions.

[ken0042]

Originally Posted by MelBridgeman

It is a god sent when driving in a winter storm on a 2 line highway

I did find it useful once in a fog, but equally useless another time after having a blowout.

Long story short, I was driving home from camping; sick and tired. Spent 2 hours changing the tire after a blowout because the factory tire iron didn't fit the bolts. So I'm on 2 lane hwy and quickly find why they say not to exceed 80km/h on those temporary spare tires. At 95 km/h the tire was too hot to touch after stopping. So there I am doing 85 in a 100 zone on a 2 lane hwy the Monday of an August long weekend. I didn't dare drive onto the shoulder to let people pass as I wasn't sure how much of that rough road that tire could withstand.

[Clever_Iggy]

I've also heard that proper alignment for your car is supposed to slightly veer you to your right if you let go of the wheel. The theory behind this is so if you fall asleep/stop paying attention, your car will gradually go into the ditch rather than into oncoming traffic.

I dont know if this is exactly true, but it's what the alignment guy told me awhile ago.

[CrusaderPi]

Hey, as long as we're asking questions, is something a "God sent" or a "God send". I've always said "God send" but now I'm worried I've been making a NSFL dad out of myself.

[Dan02]

Originally Posted by Clever_Iggy

I dont know if this is exactly true, but it's what the alignment guy told me awhile ago.

I think that's code for i'm not sure what i am doing exactly.

and it's god send

[disco_inferno]

i think they are phasing rumble strips out in some areas where freezing/thawing can become an issue because they retain water, and as for if you were to drift into oncomiong traffic:

i think roads are crowned (sloped) so that your vehicle (if you doze off) will drift towards the ditch (granted your steering is properly aligned and working properly...)

[jammies]

The correct answer is "Pedestrians".

[Locke]

The Rumble Strips?

They're supposed to wake you up/warn you.

On the highway they sometimes have them on the yellow lines that seperate each direction too.

[CaptainCrunch]

The remains of murdered hobos

[Dion]

Originally Posted by Clever_Iggy

I've also heard that proper alignment for your car is supposed to slightly veer you to your right if you let go of the wheel. The theory behind this is so if you fall asleep/stop paying attention, your car will gradually go into the ditch rather than into oncoming traffic.

I dont know if this is exactly true, but it's what the alignment guy told me awhile ago.

I dunno about that. If i'm cruising down the highway i can take my hands off the wheel and my Escape tracks fairly straight. I always thought a slight pull meant your alignment was out of wack.

[QuadCityImages]

Don't you guys have rumble strips before upcoming rural stop signs? Here in the midwest US, like certain distances out from a rural stop sign coming after a long stretch with no stop signs, they have rumble strips across the lane to keep people from dozing off and running the stop sign at high speed.

[guzzy]

It is too wake you if you doze off. THe technical term is rumble strips. Some highways now have them on the centreline of undivided highways as well.

[habernac]

Originally Posted by QuadCityImages

Don't you guys have rumble strips before upcoming rural stop signs? Here in the midwest US, like certain distances out from a rural stop sign coming after a long stretch with no stop signs, they have rumble strips across the lane to keep people from dozing off and running the stop sign at high speed.

yep, they have those here as well.