<html><head></head><body><div class="ydpac993d09yahoo-style-wrap" style="font-family:times new roman, new york, times, serif;font-size:16px;"><div><div dir="ltr" data-setdir="false">Hi Mark,</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"> <div><p class="ydp6b14d808MsoNormal" style="margin-bottom:0cm;line-height:normal;background:white"><span style="font-size:12.0pt;font-family:Times New Roman,serif;mso-fareast-font-family:Times New Roman;color:black;mso-fareast-language:EN-GB">I quite agree with
your pragmatic approach to this.</span></p>
<p class="ydp6b14d808MsoNormal" style="margin-bottom:0cm;line-height:normal;background:white"><span style="font-size:12.0pt;font-family:Times New Roman,serif;mso-fareast-font-family:Times New Roman;color:black;mso-fareast-language:EN-GB">However, it
re-ignites a question in my muddle of a brain.</span></p>
<p class="ydp6b14d808MsoNormal" style="margin-bottom:0cm;line-height:normal;background:white"><span style="font-size:12.0pt;font-family:Times New Roman,serif;mso-fareast-font-family:Times New Roman;color:black;mso-fareast-language:EN-GB">(Please Note: This is
NOT a really serious issue; just something of a philosophical question,
prompted by my wife's new car, which has a speed limit display on the dashboard
- I must get her to drive me through this situation and see what it says.)</span></p>
<p class="ydp6b14d808MsoNormal" style="margin-bottom:0cm;line-height:normal;background:white"><span style="font-size:12.0pt;font-family:Times New Roman,serif;mso-fareast-font-family:Times New Roman;color:black;mso-fareast-language:EN-GB">In a situation where
there are no speed limit signs (so the National Speed Limits apply) and a dual
carriageway (70 mph) and a single carriageway (60 mph) cross each other with a
roundabout, what is the speed limit on the roundabout? </span></p>
<p class="ydp6b14d808MsoNormal" style="margin-bottom:0cm;line-height:normal;background:white"><span style="font-size:12.0pt;font-family:Times New Roman,serif;mso-fareast-font-family:Times New Roman;color:black;mso-fareast-language:EN-GB">As I said, it is a
philosophical question, as I am unlikely to exceed 60 mph going round a roundabout!</span></p></div><br></div><div><br></div><div class="ydpac993d09signature"><div style="font-family:new times, serif;font-size:16px;"><div>Regards,</div><div dir="ltr">Peter</div><div dir="ltr" data-setdir="false">(aka PeterPan99)</div></div></div></div><div><br></div><div><br></div>
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On Tuesday, 15 February 2022, 10:07:36 GMT, Mark Goodge <mark@good-stuff.co.uk> wrote:
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<div><div dir="ltr"><br clear="none"><br clear="none">On 15/02/2022 06:55, Tom Crocker wrote:<br clear="none"><br clear="none">> Hi DaveF, I'm intrigued. I thought the large speed sign did mark the <br clear="none">> point of the change in legal speed limit, although of course approaching <br clear="none">> the junction it wouldn't actually be safe to travel at that speed. I <br clear="none">> remember the teacher on my speed awareness course (oops) making a <br clear="none">> similar point and "Know your traffic signs" [1] seems to say this. Am I <br clear="none">> missing something?<br clear="none"><br clear="none">This is one of those situations where there is no single "right" answer, <br clear="none">because, like a lot of legal matters, the law allows for a certain <br clear="none">amount of pragmatic fuzziness in implementation.<br clear="none"><br clear="none">Any deviation from the national default speed limit requires that the <br clear="none">new limit is imposed by a Traffic Regulation Order (TRO). But a TRO is <br clear="none">not in force unless indicated by signs. That is, both a TRO and signage <br clear="none">are necessary conditions for an enforceable speed limit, but neither <br clear="none">alone is sufficient. If there is a TRO but no signs, then the TRO has no <br clear="none">effect. If there are signs but no TRO, then the signs have no effect.<br clear="none"><br clear="none">In cases like the Hood Lane 20mph limit, it's normal for the TRO to be <br clear="none">applied to the entire street - the actual wording will usually just name <br clear="none">the street and its classification number. But the signs will be erected <br clear="none">at a point where it is most convenient or appropriate to do so, which <br clear="none">may not be right at the end of the street.<br clear="none"><br clear="none">What that means in practice is that the enforceable speed limit - the <br clear="none">stretch on which you could be ticketed for doing 25mph by a policeman <br clear="none">with a speed camera - starts and finishes at the signs. But the TRO <br clear="none">imposing the limit will cover the whole street. It just won't be in <br clear="none">force at the stubs at each end.<br clear="none"><br clear="none">How you map this is, therefore, a matter of interpretation. One option <br clear="none">would be to map the limit as only being between the signs. If you were <br clear="none">mapping a speed limit change on a continuous road - eg, where a road <br clear="none">crosses the boundary of an urban area - then you would certainly map the <br clear="none">change as being precisely where the signs are. But where the limit <br clear="none">change is associated with a junction (as here, at Hood Lane), and it <br clear="none">just so happens that the signs are set back slightly from the junction, <br clear="none">then, in practical terms, it may well make more sense to map the limit <br clear="none">as extending to the junction because that's more useful to consumers of <br clear="none">the map. Even though that short stretch between the junction and the <br clear="none">signs does not have an enforceable 20mph limit, the reality is that <br clear="none">nobody is going to be going that fast anyway at that point and having a <br clear="none">short stretch mapped as 30mph is liable to confuse things like sat-navs <br clear="none">which include speed limits in their data.<br clear="none"><br clear="none">So, in this particular case and others like it, I would tag the entire <br clear="none">street as having a 20mph limit. That's not necessarily the most <br clear="none">pedantically correct option, but it is the one which is most appropriate <br clear="none">for the on-the-ground conditions. And, while OSM not in any way obliged <br clear="none">to follow the conventions used by other mapping agencies, most of those <br clear="none">which use speed limit data (eg, sat-nav map providers) would tag the <br clear="none">entire street as having a 20mph limit here.<br clear="none"><br clear="none">Mark<div class="ydp3702cd5dyqt4060314741" id="ydp3702cd5dyqtfd13835"><br clear="none"><br clear="none">_______________________________________________<br clear="none">Talk-GB mailing list<br clear="none"><a shape="rect" href="mailto:Talk-GB@openstreetmap.org" rel="nofollow" target="_blank">Talk-GB@openstreetmap.org</a><br clear="none"><a shape="rect" href="https://lists.openstreetmap.org/listinfo/talk-gb" rel="nofollow" target="_blank" fg_scanned="1">https://lists.openstreetmap.org/listinfo/talk-gb</a><br clear="none"></div></div></div>
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