Tactile paving

[fanf]

In Britain there is a standard for tactile paving at the start and end of shared-use foot / cycling paths. It uses a short section of ridged paving slabs which can be laid with the ridges either along the direction of the path or across the direction of the path, to indicate which side is reserved for which mode of transport.

Transverse ridges

If you have small hard wheels, like many pushchairs or the front castors on many wheelchairs, transverse ridges are very bumpy and uncomfortable.

If you have large pneumatic wheels, like a bike, the wheel can ride over the ridges so it doesn't feel the bumps.

Transverse ridges are better for bikes

Longitudinal ridges

If you have two wheels and the ground is a bit slippery, longitudinal ridges can have a tramline effect which disrupts you steering and therefore balance, so they are less safe.

If you have four wheels, the tramline effect can't disrupt your balance and can be nice and smooth.

Longitudinal ridges are better for pushchairs

The standard

So obviously the standard is transverse ridges for the footway, and longitudinal ridges for the cycleway.

(I have a followup item with a plausible explanation!)

Comments

[fanf]

Apart from compatibility with the installed base, I'm not aware of any way in which the current standard is better than the other way round, and it's clearly worse in three ways.

[cartesiandaemon.livejournal.com]

I'm sorry, I don't understand how you read my comment? Clearly the current convention is awful and the reverse would be better. But is that the best possible convention? I don't know, but not necessarily. Is it the least intrusive? I don't know. Would it line up with the convention used at crossings and dropped curbs? I'm don't know. Are ridges (rather than some pattern of dots, or some other pattern) the best pattern? I don't know.

If the reverse of the current situation is the only possible sensible configuration, then yes, there's no good option. But if some other configuration is better than either, and sufficiently different it's not confusing, then we could use that for new installations. Then there would be a long transition period, but at least once you were familiar with the types one particular piece of it would be unambiguous. You would avoid the problems of "sometimes it means this, sometimes it means the opposite" and "have to relay them simultaneously all over the country".

I'm not sure if you already knew no other configuration would work, or read my post as the opposite of what I was trying to say?

[kaberett.livejournal.com]

(And you'd also avoid the problem of, the current standard is an international standard, and while in the UK one drives on the left rather than the right I'm not convinced the downsides of deliberately going counter said international standard are worth it...)

[cartesiandaemon.livejournal.com]

I'm really sorry, I got the impression from fanf's post that part of the problem was the current standard WASN'T compatible with standards elsewhere (either different sorts of paving in the same country, or internationally). If it is worldwide, obv there's a really high cost to doing it differently.

[fanf]

No, my point had nothing to do with other standards or other uses of tactile paving at all.

[cartesiandaemon.livejournal.com]

Ah! Sorry, I was thinking of your summary of Clive's comment. It sounded like, even if the ridges were reversed, they'd still be somewhat inconsistent, whereas now I look closer, you were implying that it would be more consistent if they were reversed.

But it still sounds like they wouldn't be completely clear. The cycleway isn't really "walk with caution", it's more like "don't walk here at all" (at least in longwise, you could cross sideways).

I'm still not sure where I went wrong. I feel like the conversation was:

Tony: This would be better the other way round.
Lnr: But it would be hard to change because if you swap some of them over, then they're always ambiguous.
Jack: But even if they're better the other way round, they're still somewhat uncomfortable. maybe some OTHER design would BOTH be more comfortable AND be safe to install incrementally without making the meaning ambiguous.
Everyone: NO!

[cartesiandaemon.livejournal.com]

And sorry, I think I was too grumpy today. It's not a disaster if we ended up at cross purposes, I was just frustrated trying to work out what was actually going on.

[lnr]

It certainly read to me like you thought there was an actual *problem* with the other way round, apart from the fact it's almost impossible to get there from here.

[cartesiandaemon.livejournal.com]

I guess. I mean, I meant I HOPED there was a problem with the other way round, because then if the best standard is some type of paving that has a tactile surface other than the ridges, we CAN adopt it incrementally, and never face the problem of "there's ridges -- but do they mean bikes (old way) or feet (new way)". But apparently "it's not perfect" sounded like "lets immediately give up and not change anything"?