[OSM-talk-ie] Mobile speed camera zones

[Colm Moore]

Hi,
Both on OSM and in the Real World™, I've done a lot of work on speed limits.
In http://www.dttas.ie/sites/default/files/upload/general/Guide_Speed_Limits_Mar_2015.pdf there are two models for writing speed limit bye-laws:* Dunmanway model - draw a line around the zone and everything inside is speed limit X and * Buttevent model - a list of roads whose speed limits are X.
When the 30 km/h zone was being expanded in central Dublin about 2005, one of the problems was the list of named streets ran to about 300, which was unmanageable. The decision was made to adopt the Dunmanway model, with a list of exceptions. That zone is coloured green here: http://product.itoworld.com/map/124?lon=-6.25884&lat=53.35106&zoom=14&fullscreen=true Note that the road signage is generally 0-30 metres inside the legally defined zone,
For OSM purposes, the big problem is that the number of ways far exceeds the number of named streets. Grafton Street alone is made up of 7 ways. It would be very useful for someone to create a method that would apply speed limits to all (public) roads within a zone.
Colm


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