[Routing] Default speed limits / built-up areas (was: Re: generalized routing format - pre-computation)

[Sascha Silbe]

On Tue, Oct 21, 2008 at 01:28:38PM +0200, Nic Roets wrote:

> You type the name of the town, click to center, then type the name of 
> the
> street. The nearest occurrence will be the first result, so clicking 
> on it
> will take you there.
>
> Implementation : Each wayType has a center point and zero or more "tag
> values", for example the name. There's an alphabetical index of the 
> names as
> well as a complicated algorithm for handling the case where two tag 
> values
> are equal by finding the nearest occurrence.
So you calculate the distance for _all_ nodes matching the name and sort 
them by distance?

>> How does it work in other countries? Are there different defaults and 
>> where
>> do they change? What "prevents" you from driving as fast inside a 
>> town as
>> you would outside?
> The US makes up more than half of our "planet".
Your point being?

> If you consider that the US
> population more than doubled during the 20th century, you realize that 
> the
> majority of US town planning took place after the invention of the 
> motorcar.
> This means you often get stretches of highway / motorway inside cities 
> with
> large shoulders, embankments and railings so that it's safe to drive 
> there
> at high speed.
So effectively you have high-speed roads with appropriate access 
restrictions (preventing people from entering them) running through the 
cities and once a road enters an area where people are allowed, there's 
a speed limit sign?

CU Sascha

-- 
http://sascha.silbe.org/
http://www.infra-silbe.de/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 481 bytes
Desc: Digital signature
URL: <http://lists.openstreetmap.org/pipermail/routing/attachments/20081022/25450ff2/attachment.pgp>