Great Britain road numbering scheme

Slightly off topic... UK road signs have a very clear and consistent color scheme based on the category of road. E.g., blue background for motorways, green background for A roads.<p>This scheme was (maybe still is) reflected in the color of roads on printed maps. Google Maps also used this scheme some years ago.<p>I understand their reasoning, but the day Google standardized on the current yellow &amp; white scheme was a sad day for this UK Maps user.

Probably the most useful numbering scheme in the UK is the postcodes. It is very accurate and simple to use. For example, if you are looking for any house you can just use the postcode instead of the actual house&#x27;s address, and 99% of the times you will arrive very close to the house by using the GPS based navigation [1].<p>It is also very easy to remember and I still remember my former school&#x27;s postcode despite have not been there for more than 20 years. It is quite an achievement given that I sometimes even forget my current car&#x27;s registration number.<p>[1]<a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Postcodes_in_the_United_Kingdom" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Postcodes_in_the_United_King...</a>

Also trains: <a href="https:&#x2F;&#x2F;twitter.com&#x2F;CalumS1991&#x2F;status&#x2F;860906439656824833" rel="nofollow">https:&#x2F;&#x2F;twitter.com&#x2F;CalumS1991&#x2F;status&#x2F;860906439656824833</a>

While are are not on the topic, anyone want to help me petition our senators to get all U.S. Interstate exits to be numbered by their mile marker rather than sequentially?<p>Know that exit 32 is at mile marker 32 provides me so much more information than knowing that exit 8 is immediately after exit 7, which could be 1&#x2F;4 mile past it or 40 miles past it.

<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Anomalously_numbered_roads_in_Great_Britain" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Anomalously_numbered_roads_in_...</a> amazing

I&#x27;m trying to think if there are any iconic roads in Britain, the way that Route 66 is in America. Ireland has the N17 (<a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=32-WdYOeJLk" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=32-WdYOeJLk</a>). The M1 is pretty famous - it runs up and down the country like a spinal column - but I can&#x27;t think of any songs. The M25, which goes round London, is known for its traffic jams and gave Orbital their name (<a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bV-hSgL1R74" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bV-hSgL1R74</a>).

The Isle of Skye is where I learned that an A road was likely the most significant road in the area, not necessarily a large, well-developed one.<p>A855 is single lane around most of the island. Not a single lane each way, but a single lane with little pullouts every so often to let oncoming traffic past. We drove extremely defensively. However, the scenery was top notch.

It&#x27;s an okay system but apathy has resulted in abnormalities, such as the A5-M1 Link Road leaving a bunch of routes in Dunstable out of zone. The A14, as conceived in the 90s, has always started out of zone because that was the easiest two-digit number to steal from another route. Many old A-roads have been chopped into pieces because of motorway replacements or to encourage heavy traffic to use more suitable routes, the end result is a bit of a mess nowadays.

The ultimate origin is obviously geographic and topographical, as first laid out by the Romans.<p>The region 4-5 boundary along the A5 is just Watling Street. It originates in London today as Edgware Road, which preserves its distinctive Roman straightness (it even has the faux-Roman Marble Arch at the start in Hyde Park):<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Watling_Street" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Watling_Street</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Edgware_Road" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Edgware_Road</a><p>The obvious exception is the boundary of the phased Roman invasion, which cuts diagonally from south-west to north-east:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fosse_Way" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fosse_Way</a><p>The Fosse Way was originally a military road to support the eponymous barrier <i>&#x27;ditch&#x27;</i> and rampart. Now it is mostly (near) the course of the A38 which does not follow the radial region 3 and does not fork from the A3 to the SW of London.<p>The regions are also approximately the division of Anglo-Saxon kingdoms: Sussex ( <i>South Saxons,</i> region 2), Wessex ( <i>West Saxons,</i> region 3), Essex ( <i>East Saxons,</i> region 1) and Mercia (er... midlands, for <i>all-the-other-Saxons,</i> regions 3~4):<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Heptarchy" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Heptarchy</a><p>Watling Street later became the border between Viking and Anglo-Saxon sectors of the island (hence the radical divergence in accents and place names on opposite sides of the road):<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Danelaw" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Danelaw</a><p>Also note that because it is essentially topographical, it was also followed by the private railways, giving LNER (region 1), SR (region 2), GWR (region 3) and LMS (aforementioned <i>Mercia</i> and west coast line, ~ regions 4,5,6), hence the originating stations in London:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;London_and_North_Eastern_Railway" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;London_and_North_Eastern_Railw...</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Southern_Railway_(UK)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Southern_Railway_(UK)</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Great_Western_Railway" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Great_Western_Railway</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Southern_Railway_(UK)" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Southern_Railway_(UK)</a><p>P.S. Direct links to Wikipedia should be banned from HN submissions.

The zone diagram at the top of the article makes London&#x27;s importance pretty clear. All roads (in England and Wales) lead to London.

The radial numbering can be a useful ‘signpost’.<p>As an anti-invasion tactic during World War II, a civil defence measure was to remove many road signs. That’d stop those nazis in their tracks.<p>So to this day, I find the UK a difficult country to navigate by signs alone as they are often absent at important local junctions.<p>In many other parts of the world, you can trace your way from a major destination by signs at forks&#x2F;exits. In the UK, this often only works on ‘M’otorway routes. With satnav now ubiquitous, much local signposting tends to deplete over time, unless it is to control traffic flow.