After having made some sprint maps up to and including WOC 2006 I had learned a few things that I made public on my home page. Since then I have made innumerable sprint maps through almost 20 years and this is an update of my experiences and opinions on sprint mapping - and to some extenct the international sprint norm.
The international norm is now ISSprOM, which on Jan 1, 2020, replaced the quite old ISSOM 2007. Both can be found at https://orienteering.sport/iof/mapping/. The map examples are all from maps drawn with ISSOM 2007.
Other language versions of the original home page:
Trees and bushes
Trees with at trunk less than 0,5 meter in diameter is shown with a small green dot (418). There is no lower limit on the size so any size tree can be shown but it has to be prominent. In some cases this means that very small trees are included.
From the overall impression of the terrain it makes sense to take overall decisions regarding how small trees and bushes to include. E.g. at JWOC 2019, we choose not to include trees that were supported like the tree on the right.
Some trees are so big and with so large a crown that reaches the ground that their appearance in the terrain is larger than the green circle of a large tree (417). In the terrain the circle is 4-5 meters in diameter but this is not sufficient for trees with crowns up to 30 meters in diameter. For WOC 2006 I "invented" a white circle around the green making the tree seem bigger on the map.
Others seems to have taken this up, so it must work.
In some cases several trees are standing so close together or have so dense crowns that the ground beneath them no longer is "grassy" but has "wood character". Especially coniferous trees can be found to do that. In that case I have also used the white forest (405).
But I do take care putting single trees inside forest. As a rule of thumb I never use 418 there - but do make excuses, like here, where the number of trees are very small.
As there is no lower limit on trees there is no lower limit on bushes. Small bushes use the same symbol as small trees (418) but larger bushes should be drawn in form. But remember that 418 is 3 m in diameter in terrain so the bushes should be quite large before drawn in form.
In this example I first used the park symbol (402) for the whole area but then I decided to draw each bush and tree by itself. I still really haven't decided whether I think that is a good idea.
Forest, park or single trees?
When deciding between the park symbol (402) or forest (405) in an area with some trees I look at the type of ground and the tree cover. If the ground is "foresty" i.e. with leaves, a few branches etc, or there is full tree cover, I use the forest symbol, as the terrain hardly can be called "open land with scattered trees" as 402 is described.
Even if the runnability is almost 120% as in this case, it is still forest. I think ISSprOM is a bit weak here, as there is no way to indicate such super runnability as 405 accepts up to 20% hindrance.
The decision between park symbol (402) and single trees depends mostly on the feasibility of marking each tree/bush. If it is possible to do so without making the map cluttered, I mark each tree and bush. You can do this in open parks where trees and bushes are almost the only features.
I tend to view 402 a bit as an "I give up" symbol.
Roads and paths
Also paths with gravel should be marked using 501. This symbol is used for any paved area regardless of it being asphalt, gravel, tiles or concrete.
The width has no influence on whether to use 501 or e.g. small path (506). Even a very small one tile wide path should use 501.
Even though there is a little grass between a path and a road it can be so small that marking it on the map is awkward. In that case I have used a single edge (501.1).
My rule of thumb is a division less than 80-100 cm in width - i.e. 0.2-0.25 mm on the map - is too small to mark. An edge by itself is 0.1 mm which is 40 cm in terrain.
In this case we have non-paved paths. Then 505 shall be used. The path to the left is small (it was smaller when then map was drawn) so 506 is used.
This also illustrates a problem with ISSprOM (and ISSOM): The difference between the two symbols (505 and 506) is huge even if they should show the same feature with only the width/size as difference.
Having edges between road and pavement is partly a matter of taste. According to the specification they should not be represented unless they serve navigation. On the other hand I find that marking them gives the runner an indication of the character of the area, in this case a road with several independent traffic sources, i.e. a big road and not a large paved area. Furthermore I find the map more aesthetic with the edges.
But if the edges is shown in some part of the map (i.e. a big road) they should be shown in all parts - for consistency.
According to ISSprOM a passable wall can be up to 1.5 m high. I think that is far too high under normal circumstances. You have to take into account that also children and elderly should use your map. That means that a wall shouldn't be too high to be considered impassable.
Even if a wall changes height from one end to the other - as seen here - you have to choose either passable or impassable wall for the entire stretch of wall. You can't expect the runners to evaluate when the wall changes from on to the other and they risk passing where prohibited.
What not to include
Neither bench arrangments - as here - nor single benches, waste baskets, street lamps, signs, football goals etc. should be represented on the map. It is stated in chapter 2.1 of ISSprOM.
Furthermore many of these things can be moved.
Even on a sprint map the minimum height of a boulder is 1 meter!
I have seen gates like these and hand rails of stairs being mapped as passable fence (516). But the minimum length of such a fence is 2.2 mm - almost 9 m in terrain. So in most cases they should not be mapped.
Another reason to leave out the gates is that it is harder for the runners to assess whether you can pass here or not.
This may be a bit controversial. What about those stairs?
They are very prominent but - as they don't lead anywhere and they clearly would clutter the map - they in my opinion shouldn't be mapped. Especially if they are normal for the terrain used.
The same goes for fire escape stairs and basement stairs commonly found at the end of apartment buildings. Mostly they will only clutter the map and they don't have any navigational value.
Finally an example of a feature that could be represented. A bus stop.
It is mostly a matter of taste. But it is important to be consistent: either all bus stops are included or they are not.