OS Maps are good, who knew?

[Ham]

Last week I was in the Peak District, walking with Mrs Ham, and managed to leave my Garmin at home. Not something I often do, but hey ho. Being a lover of maps for planning, I lashed out on OL24, the local 1:25000 map and discovered that it now comes with a free digital download.

Now the phone screen is useless as ever for planning, but having the 1:25000 combined with GPS location is actually bloody brilliant. While this is more a hiking than a biking thing, the precision and detail of the OS as compared to OSM is astonishing, so much so that I need to re-think my GPS strategy to include it somehow. It may be as simple as augmenting my handheld with a phone, but I'm 100% sold. Why not just phone? well, apart from single device battery usage, GPS accuracy, convenience of track creation, phones aren't IP67, a necessary feature for a handheld.

[Kim]

I have OS maps^[1] in Viewranger on my phone and tablet.  IMHO a 10" 4:3 screen is just about adequate to get a 'big picture' sense of the map, especially when accompanied with enough CPU power to scroll and zoom in real time, in exactly the way a GPS receiver's display isn't.

When touring, I'll use this for just-in-time planning, optionally creating Routes or Waypoints to transfer^[2] to the eTrex (which is logging, regardless of how I'm navigating).

A phone screen is still sucking maps through a straw somewhat, but perfectly adequate for checking to see where that bridleway goes.  And you probably have it with you.


As for OS vs OSM, they're different beasts, suited to different jobs.  Ideally you want both.  (I also have OSMAnd+ installed.)


(FWIW, I've tried 1:50k bitmap OS maps on an eTrex.  It's shit, being both cluttered and lacking in precision at the same time.
 And horrendously slow.  And the text only works with 'north up'.  A display like that needs simple vector maps for clarity.)



_{[1] The whole of Great Britian in 1:50k, plus one-off 1:25k tiles of areas where I've been off-roading (substitute for walking, because knees) and wanted the extra detail.  All stored locally, for obvious reasons.
[2] Android has a significant advantage over IOS here, as it gives you proper access to the filesystem and can mount USB-storage devices.}

[Phil W]

OS are great but they are not great on a small screen. I prefer OSM on the small screen of a GPS.  Often all I want when navigating on the road is to be able to see the roads and paved cycle tracks, and basic features like woodlands, and some POIs that interest me.  I do believe less is more when it comes to GPS screens and mapping.  I don't use the GPS for planning as I find they don't suit that purpose. For off road biking it's OS mapping for me nearly every time unless local and mapping etc not needed. 

I have OS, Harvey, and IGN mapping on my phone courtesy of Anquet; I've had this mapping since 2002. I can plan walking / moiuntain trips on the same mapping on my PC then sync the routes produced, should I wish (or print the mapping with overlaid routes).

[frankly frankie]

Precision and detail.  The most precise thing on an OS map is an intersection of two grid lines.  Assuming these lines are printed 0.1mm thick, on a 1:25,000 map an intersection represents an area of 2.5 metres square.  Nothing else can be located more precisely than that, even though the survey itself is more accurate most lines on the map are drawn much more thickly than 0.1mm.  Coincidentally 2.5m is similar to the level of precision available on a consumer GPS.

A node on OSM is defined to 7 decimal places, that is to the nearest centimetre, more or less.  A GPS map display (old Etrex, worst case scenario) can zoom in to about 25m across the screen, or 7 pixels per metre.  At this zoom a 2x2px point on the map represents 0.3m or about 1 foot square.  It is easy for example to view a tracklog at this zoom and tell which side of the road the rider was riding along. 
Of course OSM is a conglomerate of surveys of highly variable quality and provenance, any particular road junction could be loose/precise to within 100m (freehand drawing) or 10cm (commercial survey) and there is no way to know which when just viewing the map - but the precision range 5m to 1m probably covers most of it.  5m is ball-park comparable with OS 1:25,000.

Detail - one problem with OSM is that in some places (notably some university towns where the mapping is over-researched) there is far too much detail.  Bus stops, post boxes, bike racks, real-ale pubs, all lovingly pinpointed.  Apart from road mapping, in France for example they are obsessed with property boundaries, in fact these were mapped long before the roads were, back when OSM was evolving.  In open country - yes OS mapping wins.  Anywhere in the world outside of the UK - open country or not - OS is a fail.

[Ham]

Anywhere in the world outside of the UK - open country or not - OS is a fail.

....if only because OS doesn't exist outside the UK?

[FifeingEejit]

If you think OS GB mapping is good, have a look at OS-NI or OS-IRL mapping.

Every building is marked individually, so you can navigate by counting buildings if needed in areas where the survey is up-to-date.


Though the 3 OS' it appears are pretty much at the peak of national mapping, everywhere else just fails miserably.

[frankly frankie]

When it comes to beautiful and detailed cartography, I'm fond of the Swiss 'Landeskarte der Schweiz' maps. 

Didn't OS map India?  Or is that just my imagination, Googling I don't see any direct references to it.

[andyoxon]

Did my first OS map download a few weeks ago.  It's a shame the downloads don't save to SD cards, for those of us running out of phone built in memory space.

[rafletcher]

..... phones aren't IP67, a necessary feature for a handheld.

You can always pop it in an Overboard pocket.

https://www.amazon.co.uk/OverBoard-Waterproof-iPhone-Samsung-Smartphones/dp/B079RCYNQ8

[rafletcher]

Anywhere in the world outside of the UK - open country or not - OS is a fail.

....if only because OS doesn't exist outside the UK?

Indeed.  I used to use IGN paper maps in France for cycling some 30 years ago. Plenty detailed enough, and equivalent to OS. I'm sure there are other examples.

[yorkie]

Didn't OS map India?  Or is that just my imagination, Googling I don't see any direct references to it.

Possibly the Great Trigonometric Survey of India, which took most of the 19th Century?

[Phil W]

It is the Ordnance survey the clue is in the name as to what purposes they were originally surveying for.

For many Alpine areas bordering Italy and Switzerland you can get Swiss or Italian mapping. The difference is quite telling if using them in a mountaineering context.  It does of course depend how recent the survey was in terms of glaciers as they are changing all the time. Let's just say one country's version is quite imaginative with the details.

[Cudzoziemiec]

It is the Ordnance survey the clue is in the name as to what purposes they were originally surveying for.

Whether by coincidence or not, the best maps I found in Poland were produced by the Military Cartographic Department, or words to similar effect – I'd have to dig them out to find the exact name. They weren't sold everywhere though.

[andrew_s]

I've got the OS 1:50,000 for the whole of the UK on my Garmin, and find it works quite well with OSM (I generally just treat the Garmin as a moving map and make up the route as I go along, rather than following any pre-prepared route or track).

If I've just got OSM, and zoom out too far, the minor roads vanish (when the scalebar says 300m or more), which makes deciding where to go distinctly awkward.

If I've just got the OS (250k and 50k on the card), I can see all the roads for a fairly large area (scalebar up to 3 km), but if I zoom in past scalebar=200m, or maybe 120m, the map is too pixellated and covers too small an area to be very useful.

I therefore just switch maps according to what I want to see, which takes about 5-10 sec, depending on how much I look at the Garmin whilst I'm switching.

[Joe.B]

The region of Northumberland where I do much of my riding (and occasional walking), rather annoyingly requires 4 separate OS Landranger sheets.  But no more as I've just ordered a custom OS map with the Tyne along its southern edge and the A1 along its western edge, meaning that most of our family rides will be contained on a single sheet.  Not a bad for £14.40 including postage.   

[Phil W]

If I've just got OSM, and zoom out too far, the minor roads vanish (when the scalebar says 300m or more), which makes deciding where to go distinctly awkward.

That's a feature of when the OSM data was converted into Garmin format.  For every map feature it can be decided at what zoom levels they appear or disappear. You can even have a road appear in one style at one set of zoom levels and have a different appearance when zoomed in for instance.  So get a different map based on OSM and you may well still see the minor roads when zoomed out.  You can also change the map settings on your GPS to show more or less detail. More detail and the minor roads often show up when zoomed out further. Being vector no pixelation when zoomed in either.

[Paul]

Is this the wrong place to say that the the 1:25 000 paper maps are awesome?

They fit in a (big) pocket.

They don't need to be charged.

You can read them with your eyes (including glasses)

A torch works on them in the dark.

If you have a compass or daylight, you can find the 'up'.

You can write things on them.

[Kim]

All true, but they're more than a bit unwieldy for road cycling, and the place you're interested in is nearly always at the intersection of two or more maps.  (There's a lot to be said for printing your own excerpt from electronic maps, or using a service like Joe.B refers to.)

TBH, my favourite place for the 1:25k maps is on the wall.   

[Paul]

TBH, my favourite place for the 1:25k maps is on the wall.

But it does make the cycling tricky.

[Kim]

TBH, my favourite place for the 1:25k maps is on the wall.

But it does make the cycling tricky.

I'm sure there are some useful tips to be had from Danny MacAskill's videos.

[matthew]

If you are cycling using an OS 1:25,000 then you aren't going far before you are off the map. One of the biggest items on our family tours was the collection of OS 1:50,000 maps that were required. I now tend to use the OS 1:250,000 as they show all the surfaced roads which I want to use and a two week tour only needs one or two.

[Kim]

One of the biggest items on our family tours was the collection of OS 1:50,000 maps that were required.

And this is where electronic mapping is a massive win.  MicroSD cards are magic.

[matthew]

One of the biggest items on our family tours was the collection of OS 1:50,000 maps that were required.

And this is where electronic mapping is a massive win.  MicroSD cards are magic.

Such electronic devices weren't available between 1988 and 1998 that would also run all day on battery and not weigh more than the maps.

I believe on the Berks - Manchester tour dad posted half the maps to the rest day location in advance and posted the used maps home from there, but more normally our tours were loops so the first map was also the last.

[andrew_s]

If I've just got OSM, and zoom out too far, the minor roads vanish (when the scalebar says 300m or more), which makes deciding where to go distinctly awkward.

That's a feature of when the OSM data was converted into Garmin format.  For every map feature it can be decided at what zoom levels they appear or disappear. You can even have a road appear in one style at one set of zoom levels and have a different appearance when zoomed in for instance.  So get a different map based on OSM and you may well still see the minor roads when zoomed out.  You can also change the map settings on your GPS to show more or less detail. More detail and the minor roads often show up when zoomed out further. Being vector no pixelation when zoomed in either.

I am aware.

I do have a different version of OSM that shows minor roads out to scalebar 1.2 km, but unfortunately they are very thin and not readily distinguishable from streams or town/village/woodland shading when the GPS is on a moving handlebar.
The trouble with more detail is that you also get more of the clutter you aren't interested in.

The solution would be to bake my own maps according to my requirements and preferences, but I don't want it enough to put in the required time and effort.

[Ham]

Is this the wrong place to say that the the 1:25 000 paper maps are awesome?

They fit in a (big) pocket.

They don't need to be charged.

You can read them with your eyes (including glasses)

A torch works on them in the dark.

If you have a compass or daylight, you can find the 'up'.

You can write things on them.

Actually, they've lost a couple of awesome-stars for me as a result of their current habit of printing on both sides of the paper. I'm sure it adds to the value, but the usability is not improved. However, the dual format  where both sides are a single page on your device goes some way to  making up for that.