[Talk-GB] maxspeed field - what units should we use. etc

Peter Miller peter.miller at itoworld.com
Thu Jun 4 17:34:43 BST 2009

On 4 Jun 2009, at 17:11, WessexMario wrote:

> Robert Naylor wrote:
>>>> On Thu, 04 Jun 2009 11:13:28 +0100, David Earl
>>>> <david at frankieandshadow.com> wrote:
>>>>> I also came across someone tagging maxpeed=NSL yesterday. If it  
>>>>> gives
>>>>> someone happiness, fine, but I don't really think it should be
>>>>> necessary
>>>>> to tag the default situation, only when there is an exception to  
>>>>> the
>>>>> general rule
>> This page seems to confirm this:
>> http://www.abd.org.uk/know_your_speed_limits.htm
> There is a major problem with using maxspeed=NSL.
> Dual Carriageways.
> How will the applications know that a way is part of a dual  
> carriageway
> or is just one oneway way that happens to be near another oneway way?

Here is a proposal for using relations to combine carriageways and  
also one for collecting together all the slip-roads into a single  
feature called 'junction':-

"To avoid duplication, the name/ref of the street should continue to  
be placed on the Ways of the street or in the Relation for the  
collected ways of a street. This relationship is only intended as a  
hint to renderers that the adjacent ways are actually part of the same  
street/road so the name could be positioned between the carriageways  
rather than in both, or the road number rendered only once for  
adjacent pairs of ways and similar applications.

And this one for interchanges
"The main purpose of the Relation at present is to give renderers or  
route planners a name and or number for a junction. It also means that  
a staggered cross roads controlled by linked traffic signals can be  
grouped into the one junction while still maintaining the geometry of  
the streets correctly.



> _______________________________________________
> Talk-GB mailing list
> Talk-GB at openstreetmap.org
> http://lists.openstreetmap.org/listinfo/talk-gb

More information about the Talk-GB mailing list