Discussion: Contour feature & route choice
in: Orienteering; General
Jan 28, 2002 10:35 PM
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Sorry this question is a bit long, but the details are important.
SLOC has a 1:10000 map of West Tyson park that we use quite a bit. The map was most recently updated by Plamen Djambazov in 1996. Everybody agrees that it is an excellent map. The park itself is comprised of some very steep ridges (about 80-100m high) in the south draining into a flood plain in the north. About 60m above the flood plain is a layer of rock that has held up better to erosion than the rest. On the southern part of the map this can be seen as an exposed cliff.
The interesting bit is in the north, where the rock is not exposed. Here, the only evidence is a nearly flat ledge following the same contour around the otherwise steep slopes. Since it’s nearly impossible to set a course at Tyson without encountering this feature, all the locals know about it. We refer to it as the “highway” because you can run pretty much full speed on it.
Since this is a natural feature, the only indication on the map is that there is a slight gap in the tightly spaced contour lines. While this is enough to pick it out if you know it’s there, it is certainly no indication of how much faster one can travel compared to traversing the steep slope. At a practice session yesterday, I set a leg that could follow the highway most of the way around a ridge or pop over the top. After comparing splits we found the highway to be about 20% faster than the direct line. Without the highway, the around route would be ridiculous.
So, with that background, here’s the question: suppose a course setter really wanted to offer that leg because of the interesting route choice. What would be the best way to do this and be fair to those that didn’t already know the map? Some options that I considered were:
1) Put something in the course notes indicating that the gap in the contour lines is actually a flat ledge.
2) Add a ride to the map. This is technically inaccurate because it’s a natural feature, but it does look a lot like an abandoned road and has about the same impact on speed.
3) Exaggerate the gap in the contour lines. This would get the message across, but the highway is only a few meters wide at places. Someone expecting a wide ledge might miss it.
4) Throw out the leg. I don’t like this solution much, but without a better option, the leg is unfair.
Any and all opinions welcome.
SLOC has a 1:10000 map of West Tyson park that we use quite a bit. The map was most recently updated by Plamen Djambazov in 1996. Everybody agrees that it is an excellent map. The park itself is comprised of some very steep ridges (about 80-100m high) in the south draining into a flood plain in the north. About 60m above the flood plain is a layer of rock that has held up better to erosion than the rest. On the southern part of the map this can be seen as an exposed cliff.
The interesting bit is in the north, where the rock is not exposed. Here, the only evidence is a nearly flat ledge following the same contour around the otherwise steep slopes. Since it’s nearly impossible to set a course at Tyson without encountering this feature, all the locals know about it. We refer to it as the “highway” because you can run pretty much full speed on it.
Since this is a natural feature, the only indication on the map is that there is a slight gap in the tightly spaced contour lines. While this is enough to pick it out if you know it’s there, it is certainly no indication of how much faster one can travel compared to traversing the steep slope. At a practice session yesterday, I set a leg that could follow the highway most of the way around a ridge or pop over the top. After comparing splits we found the highway to be about 20% faster than the direct line. Without the highway, the around route would be ridiculous.
So, with that background, here’s the question: suppose a course setter really wanted to offer that leg because of the interesting route choice. What would be the best way to do this and be fair to those that didn’t already know the map? Some options that I considered were:
1) Put something in the course notes indicating that the gap in the contour lines is actually a flat ledge.
2) Add a ride to the map. This is technically inaccurate because it’s a natural feature, but it does look a lot like an abandoned road and has about the same impact on speed.
3) Exaggerate the gap in the contour lines. This would get the message across, but the highway is only a few meters wide at places. Someone expecting a wide ledge might miss it.
4) Throw out the leg. I don’t like this solution much, but without a better option, the leg is unfair.
Any and all opinions welcome.
Jan 29, 2002 3:34 AM
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How about setting a leg in the beginning of the course that would force everyone to use the "highway" (say a short leg that made everyone use the highway)? Then everyone would have a chance to see the feature and see how it is mapped.
Another option would be to put a note with an example of the map at the start. I'd say that is a better option than putting it in the course notes.
You could also just ignore it and let the locals have an advantage.
Mapping it as a ride is, in my opinion, the worst solution. A better solution would be to create some sort of special symbol -- maybe a dashed line of some sort.
This discussion thread is closed.