[mkgmap-dev] [PATCH v1] modify road speed and class from a POI

Wed Oct 14 09:38:16 BST 2009

On Wed, 14 Oct 2009 08:45:52 +0200
Ralf Kleineisel <ralf at kleineisel.de> wrote:

> On 10/14/2009 01:14 AM, Mark Burton wrote:
> 
> > These tags expect an integer value, optionally preceded by a + or -
> > which make the adjustment relative to the original value.
> 
> This is a good idea.
> 
> But I think it would be better to allow for non-integer values of
> adjustment. E.g. if I have a long street through a city with 10 traffic
> lights I don't want it to end up with a road_speed of -8. This might route
> me through small narrow side streets. A correction value of "-0.1" for every
> traffic light might be better. The value can be rounded to the nearest
> integer after all corrections are applied.

Yes, avoiding multiple adjustments is required, well spotted. I will
add that in. I am not keen on the decimal adjustment. Remember, the
region that has the change applied to it is limited in length so if you
had multiple lights/crossings along a particular road, it would be
segmented into regions that alternated normal/slow/normal/slow..

> Another suggestion: Add the possibility to mark a road with a minimum and
> maximum road_speed it can ever get when being corrected in the above way. E.g.:
> 
> highway=primary [road_speed=4 min_road_speed=2 max_road_speed=5]

It's getting complicated, let's see how we get on with what we have (+
the extra needed to avoid multiple changes as discussed above).

Cheers,

Mark