[OSM-talk] How to use lanes= for two way single track roads?

[Jo]

Andy Robinson (blackadder) wrote:
> Bruce Cowan wrote:
>   
>> Sent: 13 March 2008 2:28 AM
>> To: DavidD
>> Cc: talk at openstreetmap.org
>> Subject: Re: [OSM-talk] How to use lanes= for two way single track roads?
>>
>> On Wed, 2008-03-12 at 21:09 +0000, DavidD wrote:
>>     
>>> According to map features the value for the lanes key should be.
>>>
>>> "Number of travel lanes in each (or only permitted) direction"
>>>
>>> I've been tagging to this definition.
>>>
>>> "Number of travel lanes on the way"
>>>
>>> This makes more sense to me because you can tag two way single lane
>>> roads with lanes = 1. The map features definition on the other hand
>>> doesn't give an obvious way to tag these roads. lanes = 0.5 perhaps.
>>>
>>> I didn't pick up the lanes tag from map features but some other wiki
>>> page. I'm sure the wiki page defined the lanes key similarly to my
>>> definition. Unfortunately I know can't find that wiki page to check.
>>>
>>> Was the lanes tag added to map features wrongly?
>>>       
>> While thinking about the many roads up here that are single tracked,
>> it'd be quite useful to be able to map them properly. The result was
>> passing places [0]. I am under the impression that lanes=1 means 1 lane
>> each way, but this makes these roads impossible. I'd quite like another
>> tag, such as narrow=true (or something non-boolean) which would mean the
>> lanes number is number of lanes overall as opposed to in either
>> direction.
>>     
>
> This why the original intention was that lanes was equal to the number of
> running lanes on the physical way. In your case it would be lanes=1 except
> (if you like) at passing places where lanes=2. Since a passing place is a
> very short length normally it would be simpler to tag a node with lanes=2 at
> each passing place. Isn't that the simplest method and easily understandable
> in the data?
>   
That seems a lot more logical than what is done now. lanes is the 
physical number of lanes on a road/carriageway. What would be nice would 
be the ability to also indicate the direction and also whether it's a 
lane for making a turn left or right or going straight ahead. It should 
of course be possible to have more than one lane for turning/going 
straight as well.

Jo