What's the story with lane splitting?

[ManDownUnder]

Are they actually called Tar Snakes or do they have a proper name?
(for when I complain about them, dont want to sound like a moron)

Tar snakes is good - drag 'em down to my level!

[Whynot]

"Enough is enough! I have had it with these motherfucking tar snakes on this motherfucking road!".

[bert_is_evil]

Tar snakes is good - drag 'em down to my level!

Not to be confused with the road snakes found in Napier:
http://www.stuff.co.nz/3906112a11.html

[Squeak the Rat]

That's a bit rough. It was obviously a joke. Flick Joni a PM and ask her to reverse it.

Cheers Ixion, but I'm not too fussed. I actually think it's quite funny - a lot of threads on KB go off topic, but this has got to be the first that's gone from drivel onto topic!

.

[Drum]

..... Whats with those grooves cut into the road around Lower Hutt? ......Hated them.

As you deduce, they are cut into the road to provide additional resistance against sideways sliding (techincally, they provide additional macro texture). They are typically installed when the seal skid resistance is deficient, but the road is not due for a reseal, or the camber on the road is not right (which is expensive to fix).

I have never liked this method, it is a typical "band aid to fix a broken back" remedy.

[Drum]

Are they actually called Tar Snakes or do they have a proper name?
(for when I complain about them, dont want to sound like a moron)

Typically called crack-sealing or overbanding. (we dont use tar on New Zealand roads).

[xwhatsit]

As you deduce, they are cut into the road to provide additional resistance against sideways sliding (techincally, they provide additional macro texture). They are typically installed when the seal skid resistance is deficient, but the road is not due for a reseal, or the camber on the road is not right (which is expensive to fix).

I have never liked this method, it is a typical "band aid to fix a broken back" remedy.

You bring up an interesting statement there -- about `macro texture', as you put it. I've always wondered about this; the difference in grip between smooth asphalt, and coarse chip seal. Now, obviously you want to maximise the amount of rubber touching the road; so you would think that smooth asphalt would be the best option. But on the other hand... instinctively you feel that the coarse chip seal would be grippier, because it's got all these sharp bumps and stuff that you think would `grab'. In your words, the chip seal has more macro texture. Where's the line between more grip from contact, and more grip from texture?

[Drum]

You bring up an interesting statement there -- about `macro texture', as you put it. I've always wondered about this; the difference in grip between smooth asphalt, and coarse chip seal. Now, obviously you want to maximise the amount of rubber touching the road; so you would think that smooth asphalt would be the best option. But on the other hand... instinctively you feel that the coarse chip seal would be grippier, because it's got all these sharp bumps and stuff that you think would `grab'. In your words, the chip seal has more macro texture. Where's the line between more grip from contact, and more grip from texture?

A-ha! You have stumbled on the difference between macro-texture and micro-texture!

Chipseal, which is little chips of gravel/ metal in a bitumen "glue", works because of the resistance between your tyre and the bits of the gravel that stick out of the bitumen. This is known as macro-texture.

Asphaltic Concrete, the smooth stuff on the motorways, is actually porous (i.e. water can go through it), and it works by the resistance between your tyre and the edges of all the little holes in the asphalt (which let the water through) . Your tyre (on a microscopic level) actually extends into each of the little holes. This is micro-texture.

AC is generally a better surface because it is porous. The water goes down through it and then out to the side. With chipseal the water runs across the surface to the edge/ kerb. AC is also structural, it takes load from vehicles and so the basecourse below lasts longer. Chipseal is merely a seal to keep the water off the basecourse below.

AC becomes slippery when the little holes get filled by dirt (i.e. the water no longer drains away). Chipseal gets slippery when the edges of all the little chips becomes polished/ rounded.

EDIT: Apologies to Squeak for getting your thread on-topic!

[tl_tub]

The majority of asphalt is not porous (or not designed to be), the mixes used around town - mix 10 to mix 20 (10 or 20mm nominal maximum aggregate size)

You usually have to go to the asphalt used on motorways to get any decent level of porosity, this is called OGPA, open graded asphalt mix

[surfer]

All I know is splitting my trousers doesn't concern me too much because there (fortunately) is not a max size on a trouser snake.

If I see it in the road I will ride over it then, now that we all know it adds to side ways resistance

[M1CRO:Me]

AC becomes slippery when the little holes get filled by dirt (i.e. the water no longer drains away). Chipseal gets slippery when the edges of all the little chips becomes polished/ rounded.

Ok, I'll bite.. Well not hard anyway...
So.. Referring to AC, when the holes get blocked up, how do they get unblocked? Or dont we care? Or is that when it gets replaced (at some point, but generally 2-4 weeks before the end of the financial year)

[Motu]

I hear lane splitting was invented by Chuck Norris....Make sure he doesn't split a lane near you.

[Lou Girardin]

Tar snakes? Pah! bloody amateurs, we have tar anacondas around here.
(will this get moved to the herpetology forum?)

[Drum]

The majority of asphalt is not porous (or not designed to be), the mixes used around town - mix 10 to mix 20 (10 or 20mm nominal maximum aggregate size)

You usually have to go to the asphalt used on motorways to get any decent level of porosity, this is called OGPA, open graded asphalt mix

True, but I was trying to keep it simple.

[tl_tub]

True, sorry.. I was bored and have had enough of work