Road Gradient info - where can I get it?

Submitted: Tuesday, Mar 10, 2009 at 11:48
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Is there a web site that shows maximum road gradients for major roads over ranges?

Now that we carry and tow much heavier weights, I need to consider this in our travel planning.

We recently did Cunningham's Gap, fully loaded and towing the Kedron. We pulled up the hill (very long as those who have done it will know) well, but in 2nd gear most of the way.

We are soon heading from Gold Coast to NT again and one of the routes we have previously used is via Toowoomba. I'm thinking the climb at the top of the range into Toowoomba is much steeper than anything at Cunningham's Gap, but that is a perception from memory only - I don't have the data. My first thought is to avoid the Toowoomba range climb and head North up the Bruce highway, before heading West (lots of options), but all are longer and they all cross the range at some point.

It got me thinking though, that it would be handy to have access to this sort of data when planning. Truckies must have access to it, or do they just learn by collective mistakes and experience?

From our experience with climbs that have the gradient marked, up to 12% is fine. Above that is worth avoiding if we can. We did a 14% climb recently and I needed 1st gear for the last 50 meters. If the climb was much longer or steeper, it might have been low range! A run up often helps, but that is not always practical due to windy roads, other traffic, other safety considerations and just not knowing what is ahead.

Norm C
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Reply By: austastar - Tuesday, Mar 10, 2009 at 12:49

Tuesday, Mar 10, 2009 at 12:49
In Googlemaps, if you look at the terrain view, you can see the contours, that will give you the heights of start and finish. (total)
Then use google maps to get directions from start to finish, that will get you the distance of the climb. (total)

I imagine you would also be interested in the steepest section, so look at the contours where they are closest and do the same to work out that bit too.

cheers

dave
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Reply By: ExplorOz - David & Michelle - Tuesday, Mar 10, 2009 at 12:52

Tuesday, Mar 10, 2009 at 12:52
Norm,

Interesting - I am in the process of writting one of these tools for the ExplorOz mapping engine and treks systems. It is still a little way off but is certainly in the process of being developed.

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Follow Up By: Member - Norm C (QLD) - Tuesday, Mar 10, 2009 at 15:15

Tuesday, Mar 10, 2009 at 15:15
That is good news David. Others might have different views, but it is the maximum gradient that interests me. Long steady uphill hauls (like Cunningham's Gap) are no problem with a well maintained vehicle with no overheating problems. It is the occasional very tight pinches within these rises that have the potential to bring one unstuck when towing and carrying a heavy load.

If your proposed tool can provide this sort of info, it will be very helpful.

Norm C
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Follow Up By: ExplorOz - David & Michelle - Tuesday, Mar 10, 2009 at 20:18

Tuesday, Mar 10, 2009 at 20:18
Norm,

I have managed to kill a few hours today and have now installed a new altitude tools that uses STRM altitude data to compute the height of any lat/long pair that it passed to it. I am now working to use this new service in places and the new mapping tool however I reckon I should be able to show you a graphical profile on any route that you plug into the system. So you can use our driving direction tool or treknotes and request the profile be drawn and the system will deliver it. Give me a few days and it will be in a sort of test mode.

The hardest part about all this type of technical tools is the make it usable by the general public. It is really hard to design screen layout and buttons and tools that make this stuff easy to find and use so any help on these aspects once it is running will be appreciated. More as it happens however it looks really promissing.
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Follow Up By: Member - Norm C (QLD) - Wednesday, Mar 11, 2009 at 10:29

Wednesday, Mar 11, 2009 at 10:29
David, in a follow-up to Austarstar below, I raise some possible issues with implying actual road gradients from map data. I'm not sure how this will impact on the accuracy of the tool you are building.

I also understand your challenge in making such a tool usable for dummies like me.

Good luck.

Norm C
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Follow Up By: ExplorOz - David & Michelle - Wednesday, Mar 11, 2009 at 12:02

Wednesday, Mar 11, 2009 at 12:02
Norm,

I understand your issue however the new system that I have just written is using strm data collected during one of the space shuttle missions in 2001 I think. The accuracy of the data is taken using a 90m grid so basically the four corners of a 90m square were accuractly recorded - this is the most accurate altitude data available and I have compared a few hundred places in the system record using a gps and find that the answers look very accurate indeed. You can read about the data and the accuracy at the Shuttle Radar Topography Mission on the NASA site.

David
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Follow Up By: ExplorOz - David & Michelle - Friday, Mar 13, 2009 at 20:04

Friday, Mar 13, 2009 at 20:04
Norm,

In the info below please ignore the auto link to driving directions - the full driving directions page does not have this feature yet only places has this installed.

As promissed I have made up a basic (at this stage) road profiling system. It is now live in places when you request driving directions (It will be in all maps soon). For now if you go to places and find the start/end point of your road in question - I do not persoanlly know where the Gap you mention is however I found Cunningham - QLD so go to this place and in the get driving directions to box just above the map put in a town at the other end of the route I typed in Brisbane and hit Go - this will load a set of driving directions on the map - scroll to the bottom of the Directions text and there is a button called Get Profile - click it and presto a gradient profile will be displayed. It will look something like:


Now I know it is basic but I am working on it and will add the max grade information in the next updare but I just thought I would pass on the fact that I have moved forward on the project.

Let me know what you think?
David
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Follow Up By: Member - Norm C (QLD) - Saturday, Mar 14, 2009 at 10:42

Saturday, Mar 14, 2009 at 10:42
I've had a bit of a play with what you have done David and it looks good in terms of providing a big picture overview of the profile of a trip, which will be helpful. It is also pretty easy to use.

On the map that comes up for Brisbane to Cunningham, Cunningham's Gap is the section over the Great Dividing Range (marked in Green) through the Main Range National Park.

One of the others I plotted is Withcott to Toowoomba (the Toowoomba Range climb also mentioned in this thread). It shows the overall gradient to be close to 10%. I guess even without micro detail, you can draw from that info that some parts will be much steeper, so it is probably one to avoid.

On the first map, I could conclude that the overall rise is around 5% (+/-). So overall, Cunningham's Gap is a much better run, though longer. What I cannot determine (from your profile or anywhere else) so far is if there are any traps, like a 100m run of 18%.

The key to making it a good tool for detailed planning will be the amount of detail available on steepest gradients and where they are.

What you have done already is way better than anything else I have been able to find and is already a good guide for overall planning.

It will be interesting to see what you are able to provide as you develop this further.

Thanks David.

Norm C
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Follow Up By: ExplorOz - David & Michelle - Monday, Mar 16, 2009 at 16:53

Monday, Mar 16, 2009 at 16:53
Norm,

Just added a display that shows he max incline and max decline grades for the graph - it also colours the graph in these areas. The current system uses 100 selection points to build the profile so the accuracy will be increasd on a shorter route. I am working on this at the moment as really we can take heaps of points however each point takes time as I have to run a query against our altitude system for each point. I am looking to batch these functions however at the moment the system uses 100 points so for a 50km route the sampling is 500m.

Have a look at the coloured bit and the textual info and see what you think. I will be adding this feature to all our treknotes in the next few weeks so people will be able to see the profile of the treknotes.
David
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Follow Up By: Member - Norm C (QLD) - Monday, Mar 16, 2009 at 18:02

Monday, Mar 16, 2009 at 18:02
Now David, that is starting to become seriously useful.

I just plotted the Toowoomba range, which is easy to do between Withcott and Toowoomba, a distance of just over 11 KM.

It shows a maximum incline near the top of the range of just over 20%. That is STEEP. I don't know if it is accurate, but I do know that the steepest part (very steep) is at about this location, so I am prepared to trust your data.

What I need now, is the ability to focus on a short length of road like this anywhere. The other example we have used is Cunningham's Gap. I have not been able to find a way to focus just on the range crossing.Boonah to Warwick has the relevant section, but is over 100KM long. The range climb is about 15 KM long. Is there a way to hone onto the area of interest?

Clicking the start and end points on the map would be sensational, but perhaps not possible.

Other than this issue, you have achieved what I was looking for.

From my web search, what you have done is not readily available anywhere else. Well done. I hope when you launch it in final form, others will appreciate it as a planning tool as much as I do.

Norm C
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Follow Up By: ExplorOz - David & Michelle - Monday, Mar 16, 2009 at 18:10

Monday, Mar 16, 2009 at 18:10
Excellent thanks Norm glad it is working for you. Now as to the click to start/end - YES I am doing this and in fact the driving directions system uses something like this already. Give me a few days and I reckon I will have it nutted out and allow you to refine the start/end and I may even allow you to select the accuracy you are wanting ie: 50 point (low), 100 point (medium) and say 250 points (high) - SO I may make the higher accuracy only avialable to members, medium to visitors and low to the others. This may help with membership also.

I am also working at the moment on a system to allow you to build your own routes by clicking on the map and building compreshensive routes (which you can profile) and store in your account to build maps of past or future trips with all the supporting places information available to you.

Thank again for the feedback and testing when I get the start/end point thing sorted I will let you know for some more testing.

Have a good one.
DM
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Reply By: MrBitchi (QLD) - Tuesday, Mar 10, 2009 at 13:36

Tuesday, Mar 10, 2009 at 13:36
The Toowoomba range may be steep but it's fairly short so even if it requires 1st gear it shouldn't be a problem for you.

For what its worth, this link says the current gradient is max 10%.
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Follow Up By: Member - Norm C (QLD) - Tuesday, Mar 10, 2009 at 15:20

Tuesday, Mar 10, 2009 at 15:20
Interesting John. I've travelled the Toowoomba range many times (lived in Toowoomba for 3 years in the '70s). We pulled the CT up it last year with the boat on top of the Hilux.

If the 10% mentioned in your link is accurate, it should be no problem, but I must admit, my perception and memory suggests that it is steeper than that in some places.

Perhaps old age is playing tricks with my perceptions.

Norm C


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Reply By: Motherhen - Tuesday, Mar 10, 2009 at 15:18

Tuesday, Mar 10, 2009 at 15:18
Hi Norm

It would be nice to know ahead of time, then be able to select low range if necessary. When we were touring in the UK in the 1960s, any steep gradients were clearly signed with the gradient, so we could make the choice to go up it or detour.

When we were towing the Bushtracker with the Auto 3 litre Patrol (gearbox rated to tow only 2.5 t), on two occasions (once on each trip), we had standing starts on very steep tracks which slowed us down. On one, it was a winding dirt road heading up to cross a range. As we had initially taken the wrong road at a poorly signed five way intersection, we'd backed back and started up the right track from a standing start. Had we known, selecting low range would have been the way to go. The second time was in Tasmania - when we took a wrong turn up a very steep road. On both of these occasions, we think it was the auto gearbox struggling (a bit like revving an auto with the brakes on - it doesn't move).

Your Cruiser should always get you to the top, even if a bit slowly. Knowing in advance as we found in the UK would be helpful.

Our GPS (which we didn't have on the first trip) is an old model, without gradients shown. I don't know if the newer models and mapping shows gradients sufficient to help you choose the best road.

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Reply By: Member - Shane D (QLD) - Tuesday, Mar 10, 2009 at 19:47

Tuesday, Mar 10, 2009 at 19:47
Hi Norm,
I don't know where to find a gradient map, but I can tell you,The Toowoomba range is steeper, no doubt, than Cunnigham gap.

If Doug T reads this he might be able to help, The Heavy haul industry need to know how many primemovers it will need to pull/push 200 ton+ up a particular highway, as he was an escort, he may know how to source said Info.
Shane
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Reply By: austastar - Tuesday, Mar 10, 2009 at 21:57

Tuesday, Mar 10, 2009 at 21:57
If you look at google maps in terrain mode and find just East of Toowoomba, the road climbs from 400m to 600m in about 2km.
200m up in 2000m long should be about 10%.

cheers
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Reply By: austastar - Tuesday, Mar 10, 2009 at 22:32

Tuesday, Mar 10, 2009 at 22:32
If you look at the Cunningham's gap road east of the gap, it climbs from 700m to 800m in 0.6km.

i.e. 100m climb in 600m long, that should be about 16% gradient.

cheers
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Follow Up By: Member - Norm C (QLD) - Wednesday, Mar 11, 2009 at 10:24

Wednesday, Mar 11, 2009 at 10:24
This is one of the problems. From perception and driving experience, there is no way any of the gradients at Cunningham's Gap are 16%.

Also, as I said before, I'm pretty sure (but from driving experience only), Toowoomba range is more steep in parts than the worst of Cunningham's Gap. Shane seems to agree.

As a result, I get no great confidence in transferring the data from maps like this to actual road conditions.

The difference between 10% and 16% in driving terms while towing is massive - the difference between a pretty easy run and potential disaster.

So while I appreciate your efforts in calculating gradients from these maps, it does little to give confidence that I should tackle the Toowoomba range. In fact the exercise raises my concerns even further about implying these sorts of road conditions from map data.

I'm not having a go at you Austarstar. You have simply used available data to do some calculations, which don't seem to reflect the real life situation.

If I'm right, this might create a challenge for David with the tool he is building.

Norm C

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Reply By: Willem - Wednesday, Mar 11, 2009 at 09:17

Wednesday, Mar 11, 2009 at 09:17
I once had to stop and engage Low Range to get over the Hinchinbrook Jump-up on the way to Cairns. Cunninghams Gap also provided a Low Range jobbing towing the 3.5ton 27 footer over the top. I have only towed down the Toowoomba Range and also in Low Range

What I have found over the years is that the climb is not the worst thing. Its gearing down the other side.

I once went as far north as Ayr before finding an easier gradient over the ranges. I was towing a 1700kg trailer with a 2 stroke Suzuki though!

Agree however that a maps with gradient markings would be good.

Last year we were in the western deserts and my mapping showed dunes of 5 metres in height. Some of them were around 20 metres in height and not scaleable!

Cheers
AnswerID: 353366

Reply By: Axel [ the real one ] - Wednesday, Mar 11, 2009 at 12:17

Wednesday, Mar 11, 2009 at 12:17
Toowoomba climb is an avg of 10% but has a section that is 15/16% , lot shorter than Cunninghams , ,,, another way up and over is via Woodford - Yarraman - Kingaroy - Jandowae ect. not quite as steep but is longer.
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