[OSM-talk] zones for motorway/in town/outof town?

[Lester Caine]

( CHANGE THE EMAIL ADDRESS :( These odd sites that don't return list 
posts to the list ARE a pain! )

Guenther Meyer wrote:
> Am Wednesday 20 May 2009 schrieb Greg Troxel:
> we in germany have the three base zones I mentioned, but it's no problem tom 
> extend these for countries with more basic settings...

For routing purposes, the speed for each segment of a route is
important, and for speed I am sure that the ideal situation is that ALL
highway segments have their speeds assigned ( ADDING VARIABLE for those
motorway flyover routes which pass over and under the lower speed local
roads and have traffic flow management )

While a discussion on ADDING the speed zones applied by other means is
possibly useful, having to process that data to provide all of the
options for the routing software seems pointless to me, and so the roads
within those areas SHOULD simply have their maxspeed set - even if that
is applied by some blanket area rule initially.

Things like residential - with a lower limit, or school zone which
applies a lower limit during certain hours and internal 'bypasses' with
different speeds all along them all need to be set manually on the
route, so do we really need another level of complexity when simply
adding the speed to each road, and segmenting the road correctly at a
speed change sign, will get around ALL the problems and also help people
writing route finding software to identify the minimum time each section
will take.

People will claim that the application of area information via SQL
queries on a database is fast, but it still takes a lot more processing
power than doing the exercise once and being able to simply search for
routes from a list of highway segments?

So while discussing HOW the default speed for roads are calculated is
important, can we not simply apply that speed without adding another
layer of complexity? A default of the speed of a previous road section
should be all that is needed where a maxspeed is not defined .... rather
than THEN having to go to check some higher level rule.

-- 
Lester Caine - G8HFL
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