[Routing] Derive data: number of lanes and capacity

[Peter Childs]

On 8 August 2010 18:57, Paul Johnson <baloo at ursamundi.org> wrote:
> On Thu, 22 Jul 2010 13:18:15 +0200, Marcus Wolschon wrote:
>
>> Tom Müller wrote:
>>>> There is an explicit tag
>>>> lanes=<number>
>>>> http://wiki.openstreetmap.org/wiki/Key:lanes
>>
>>> yes. I know. But it's set pretty rarely. For Berlin it's set for
>>> approx. 6% of all highways ... So I was just wondering if there are any
>>> defaults which are deriveable by the highway-type or so?!
>>
>> I would assume that all highway=* to be lanes=1 (residential, secondary,
>> service,...) except motorways with lanes=2
>>
>> Maybe highway=primary be 2 lanes too.
>
> There's a lot of one-lane-each-way primaries in the US.  And thanks to
> some continent-wide data torquing by NE2, a lot of one-lane-each-way
> trunks.  The former's a fact of life, America has a lot of extremely
> rural primaries running through badlands, mountain peaks or otherwise
> just don't require extra capacity despite connecting cities.  The latter
> probably needs to be solved with a ban.
>
>

The issue is a bit more complex however.....

We have roads in the UK with.

a> 2 Lanes in each direction separated by a central reservation.
b> 2 Lanes in each direction no central reservation just a white
dotted line, (or solid depending if you can cross it)
c> 2 Lanes up and 1 down, the extra is usually up hill for crawlers
d> A hard shoulder
e> bus lanes, cycle tracks etc
etc (and any combination of the above)

truth is as has been said before we probably need some extra data
structures to hold this data, or some standardised way to do this with
relations....

Peter