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Checking gpx routes

Posted: 25 May 2019, 6:18am
by vat1666firerates1
Is there any need to check a gpx route?

Lets take two methods

1 somebody rides a route with GPX device the route is recorded and then printed off .

2 somebody plots plots plots the same route on a pc and prints in off.

3 somebody generates the same as above but keeps it in gpx format.

The above routes are then given to many non local persons with no knowledge of the area to ride.

Question

Will the routes be perfect and require no checking by a non local by riding the routes?

Re: Checking gpx routes

Posted: 25 May 2019, 6:51am
by Psamathe
Yes they would require checking depending on the source of the gpx.

I did some test to try and find a good cycle route creation service some time ago (using those online services that claim to create routes for cyclists). I created a 60 mile route that I am familiar with driving. Several created routes that I can only describe as "certain death" - they took you along the A14 near Ipswich (3 lane dual carriageway full of articulated lorries all travelling at or above the speed limit and no real "hard shoulder").

In reality and cyclist riding such a route would never cycle onto that road even when their navigator told them to, so in practice not too dangerous but could be a real nuisance as you might suddenly find you have a significant unexpected de-tour .....

n.b. last summer I used cycle.travel for a month in France and all routes it creeated were excellent and on my test route mentioned above it created a good route avoiding the A14 others seemed to take cyclists on.

But also, near me there is a nasty road for cycling (B1113). Two lane road, a lot of bends but cars so poor visibility but a lots 50 mph limit and cars travel far faster than the distance they can see and for some reason many of the club training types seem to love cycling the road (I avoid it as it's horrible, close passes as cars wanting to go at 50 try and squeeze past because you are only doing 13 mph). My point being that because one cyclist likes a route doe snot make it appropriate for everybody.

Ian

Re: Checking gpx routes

Posted: 25 May 2019, 7:06am
by PT1029
I check our club ride routes before they go on our website. Any gpx route is only as good as the plotter and software......
It depends how fussy you want to be, and who else (a friend, or public access from a club website?) might be using the route.
Your non local users with no knowledge of the local area suggests you need careful checking. Following a route using the map may need more precise checking that if following the route using left/right instructions (for which junction errors will not be seen as the rider works out how to turn left/right, even if the map route goes (say) the wrong side of a traffic island/roundabout).
Typical errors I find:-
Wrong side of traffic island.
Wrong side of roundabout (sometimes a very big roundabout...).
Mysterious short cuts across a field (which will be a bridleway or public footpath).
Specific refusal to follow a cycle track across 1 or 2 junctions (always the same few specific junctions). "Draw lines" mode in Ride with gps is the all cure for this.
Sometimes it is better to use driving mode, sometimes it is better to use cycling mode, depending on the circumstances. On Ride with gps you can switch from one mode to another while planning a route.
Small dead end side spurs off the route (which will give a left (or right) turn instruction followed by a u turn imstruction 10 yds later - which can give rise to cyclists "all over the road" if a group. Check the route fully on full zoom to detect/remove such spurs.
If in "cycling" mode, pointless crossing of the road (or even back tracking) to use a short strectch of cycle track on the other side of the road, before crossing back across the road.
Most of the above can be avoided if the plotter checks the rote properly before sending out.
Sometimes different hardware comes up with different routes, conflicting directions from 2 different makes of hardware, both routes apparently the same route down loaded from the same website!

That said, a lot of the above comes from user sloppiness/inexperience, as some members routes submitted are mostly good, some members routes submitted are consistantly bad (strava route planning seems pretty poor in this regard).
I always use lots of way points, so it follows the route I want to plan. I rarely let the software plan the exact route for me.

Maps printed off from our club website I find quite poor. Often the map looks almost alien to me, small hamlets might be marked by name, the adjoinng large village is not named at all.

One route I could have (just) ridden the 50 miles in the time I spent requesting/advising edit requests...!
I have known leaders a ride lead us (planned in "cycle" mode) rather than down the main street if a market town, but along said street using the narrow strip behind all the parked cars in that street, as that was deemed the scenic route (ie. off the main road) by the software.
Also another more remarkable one, but too convoluted to describe here!

Re: Checking gpx routes

Posted: 25 May 2019, 9:06am
by mjr
vat1666firerates1 wrote:Is there any need to check a gpx route?

Need? No. Rider beware. There's no excuse for brainlessly following the sat nav directions when you can see what's on the ground/road means it makes no sense. Is it good to check them? Yes.

Will the routes be perfect and require no checking by a non local by riding the routes?

Probably not perfect. Even marked national cycle routes which are ridden at least by Sustrans volunteers sticking up signs sometimes still contain unknown errors or known problems, so clearly someone can ride the route and still fail to spot an error.

I agree that the above common error types. Previewing a gpx before riding is often helpful. I use the Viking app on my desktop computer because then I can move/remove erroneous points easily too.

Re: Checking gpx routes

Posted: 25 May 2019, 10:25am
by Mick F
I took part in an Audax once. My first and probably my last.

The GPX route they gave out was very coarse indeed. Maybe it was ok on some devices, but the route was so coarse, it could have been interpreted differently at different junctions especially when they came thick and fast.

I sort of complained (nicely! :D ) but was told no-one else complained, so it must be ok.

I looked at the route sheet and re-plotted the route properly, and that is what I followed using my Garmin Montana.
No doubt some riders didn't have a Garmin etc and would have used the written route sheet.

As it happens, I overtook a couple of riders TWICE, so they must have taken a shortcut or their device hadn't interpreted the route correctly.

Re: Checking gpx routes

Posted: 25 May 2019, 1:01pm
by martinn
Hi Mick,
I once spent a 200 audax continually overtaking the same rider, in the end I worked it out. She had much better "control" discipline than I did :lol: :lol:

The route for an organised audax is never mandatory, you just have to hit all the controls, so those riders may have been talking a different route because they wanted to avoid a particular climb/ road/ descent or hit a particular cafe...

Martin

Re: Checking gpx routes

Posted: 25 May 2019, 1:09pm
by Mick F
Hit all the controls?
That's all?
I could have done my 107mile Audax in about 30miles
It was The Cotswold Challenge ride 17th May 2014.

I won't bother with one again. If I want to go for a long ride, I'll go for a long ride.

Re: Checking gpx routes

Posted: 25 May 2019, 5:21pm
by martinn
Hi Mick,

to explain myself better, the way the route should be planned for an Audax is that the minimum distance between the controls in the correct order, will be the minimum distance for that ride so for a 200km event, the GPX file may be 215km but the minimum distance possible measured between the controls will be 200Km.

regards

Martin

Re: Checking gpx routes

Posted: 25 May 2019, 5:49pm
by mattheus
Wow Mick - 5 years is quite some time to hold such a grudge :O

p.s. the routesheet is the official set of instructions - anything else is a bonus. And as you've found, one should always check a GPX or take the risk of some extra adventures! ;)

Re: Checking gpx routes

Posted: 25 May 2019, 8:25pm
by Mick F
Who's holding a grudge?
Not me at all! :lol:

I was cycling south after visiting Up North, and the Audax fitted in nicely. I commented on the inadequacies of the GPX route provided, and found that some cyclists didn't pay much attention to the route at all. Seems like I was wrong in my idea about these rides. No wonder I didn't see some of the starters again and overtook some riders a couple of times.

I'd have to look at the info again to see how I could have done it. I have my personal GPX track of the day of course, but unless I look it up I won't know were the controls were.

My issue generally, is that it was pointless. I don't understand Audaxes and why people do them. I had ridden from Cornwall all the way to Manchester, then down through the The Peak Disctict - (having ridden with our very own Ferrit Worrier :D ) - and south to Bedford, Swindon, Bridgwater and home.

The 107mile Audax was a bonus, but it wasn't the highlight of the trip and was a bit of an anti-climax really.

Re: Checking gpx routes

Posted: 26 May 2019, 4:39pm
by mattheus
Mick F wrote:Who's holding a grudge?
Not me at all! :lol:


OK, I'll let it lie ;)

each to his own ...

Re: Checking gpx routes

Posted: 26 May 2019, 7:33pm
by atlas_shrugged
Always check a gpx especially if it is in route point format.

Loading a file into a Garmin can have interesting results when the Garmin calculates the route. There may be three points that you wish to travel through but the Garmin may decide it knows a cunning shortcut that only goes through only two of the points. That cunning shortcut may take you on a magical mystery tour along narrow tracks and over tree roots and it ends up taking twice as long.

Not sure if a Garmin also does this 'shortcut' behaviour with a gpx file in track point format.

Re: Checking gpx routes

Posted: 26 May 2019, 8:07pm
by Mick F
If you create a TRACK and upload it into your Garmin, you will get a wiggly line to follow.
If you create a route, your Garmin will probably re-calculate it with some very strange results! :lol:
I never let my Garmin Montana think for itself and I've never let my previous Garmins either. Once bitten, twice shy.
I tell them what I want to do.


As for the Cotswolds Challenge Audax, I uploaded the GPX they gave me into BikeHikeUk to see the route on OS mapping so I knew what I was putting myself forwards for.
It was rubbish, and I said so, so had to re-do it.
I then sent it back to them.

Re: Checking gpx routes

Posted: 28 May 2019, 7:34am
by Tinnishill
This needs restating now and again, so I will take this opportunity. LEARN TO USE A MAP !

GPS is a usefull aid but not a good primary navigation tool.

Re: Checking gpx routes

Posted: 28 May 2019, 8:04am
by Mick F
My Garmin Montana is a big unit and a huge screen and has all the mapping you could need.
Paper maps not necessary.