[Tagging] Maxspeed

Paul Johnson baloo at ursamundi.org
Wed May 13 08:31:48 UTC 2015


On Wed, May 13, 2015 at 2:56 AM, Jo <winfixit at gmail.com> wrote:

> 2015-05-11 13:08 GMT+02:00 pmailkeey . <pmailkeey at googlemail.com>:
>
>>
>>
>> On 11 May 2015 at 11:40, Paul Johnson <baloo at ursamundi.org> wrote:
>>
>>> On Mon, May 11, 2015 at 4:04 AM, James Mast <rickmastfan67 at hotmail.com>
>>> wrote:
>>>
>>>> Well, in the US, I've just been tagging the 'ramp' speeds (
>>>> https://goo.gl/maps/Bw8Is ) as a normal 'maxspeed'.  I know several
>>>> other users here in the US have been doing it the same way.
>>>>
>>>
>>> Please don't, as this is confusing.  Advisory speeds are not limits,
>>> maxspeed=* is the limit, not the advisory.
>>>
>>>
>>
>> Maxspeed does not imply 'limit' by name.
>>
>> Perhaps we should have
>>
>> maxspeed:advisory=* and
>> maxspeed:limit=*
>>
>> not by name, explicitely, but that's how we've been using it since the
> very beginning. It will be really hard to change that. We also have
> maxheight and maxwidth, I think it's obvious those are hard limits, not
> advisory.
>

It's also defined as such in the wiki; for good reason, too.  How fast you
can safely traverse an obstacle varies on the vehicle.  Take, for example,
a speed table with a sharp approach and a high (6") height, and assume a
speed limit of 25 with an advised speed of 15.  On a bicycle or a unibody
sedan (and therefore, the body integrity of a windowpane), going faster
than the advised speed for the table is likely going to be somewhere
between uncomfortable and damaging to the vehicle, and a delivery driver is
likely to hit it at 10 or 15 to avoid the load shifting in his goods van or
hgv.  Whereas a large pickup or a body-on-frame SUV from the 90s is likely
to want to speed up to 30 or 35 and let the suspension take the impact fast
enough that it doesn't have enough time to shake the cab and leave the
vehicle bouncing for the next eight blocks.

That wouldn't change the fact the rational tagging is still...

maxspeed=25 mph
maxspeed:advisory=15 mph
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