Discussion: How to indicate hazard on map / course

Here's a question to which ISOM doesn't seem to provide a ready solution. I am open to suggestions how to handle it.

On an upcoming night course, there is a hazard that I want to call attention to on the map - a broken footbridge crossing a gully on a canal towpath that connects two segments of the map. Orienteers will run along the unpaved towpath for around 400 meters, as a corridor connecting two segments of the map. Since it is a flat, open run, they'll likely be moving fast. Midway through the segment, there is a broken bridge that has half fallen into a deep erosion gully. You can cross the bridge, but you have to be careful to avoid missing deck boards. In addition to missing a few deck boards, the bridge has settled, and is tilted both end-to-end and side-to-side, so if it is wet or icy, coming onto it at a run could result in a devastating fall. What can I put on the map to alert runners of this special hazard?

I can't use a forbidden route purple "X" since the towpath is a valid route and is the only connection between the two segments.

So, I will post a notice at registration warning of the hazard, but I'd also like a way to call special attention to it on the map. I'm thinking of maybe a purple arrowhead (similar to the firing range symbol but purple) pointing at that location. I also broke the path symbol so that it is mapped as if there is no bridge over the gully. (Simply breaking the path would probably be enough to call attention to it during a daylight event, but I am considering that it is in the middle of a 400 or so meter long "mindless run" segment at night, and therefore much more likely to escape notice.)

map segment

I could of course just not indicate it in any way (participants need to figure it out?), but I have concerns about participants approaching the bridge at high speed. And the park was reluctant to let us use the corridor at all (the trail is officially "temporarily" closed to public"), so I want to be sure that we've done everything we can to avoid any accidents there.

Any thoughts?

I also thought about putting a control at the gully junction just south of the bridge; having a control to find would make orienteers slow down and leave the path at that point, but due to a couple large fallen trees (honey locust which have giant thorns), I decided that wasn't a pleasant alternative either.

Recruit those HS kids to build a new bridge;)

Purple OOB overprint where the bridge is, and more importantly tape it off with caution tape on both sides, and maybe add some reflective tape so it shows up better at night.

Definitely place a barrier before the bridge, possibly with a control. Clue - Broken bridge.

If they have to cross the bridge, then you could put a control before it, and a control immediately after it. Have a timed out section of say no more than 60 seconds between these two controls, and put up as much signage and tape as you think you need to.

When we had a similar situation at the COCs in Whistler (it was a dangerous creek crossing) we did the following:
* put a control at each side of the crossing
* make the leg across the crossing 'unimed' - allowed up to 5 minutes to cross it

The idea was that people should not rush at all on this section and should pay 100% attention to crossing safely.

[EDIT - hey, that's exactly what DaveR just said too ;-0]

Sounds like you're worried about our safety.

Sounds like the park is worried about our safety.

So do what Dave suggested and have controls on either side, and then remove that split, so that people can take the time to cross as safely as possible. At the Canadian Champs in 2014, there was an untimed leg so that we could safety cross a swift flowing creek.

PS: It wasn't exactly 'untimed'. We gave people up to five minutes to cross. I can't recall exactly how we did it in the software. I think we were using MEOS and there must have been a feature that allowed us to deduct up to X minutes from a particular leg

One question though - is it possible for runners to not use the bridge? I'm not clear from your description if the bridge is the only option or just one of several. If it is possible to 'run around the bridge' then I like edwarddes' solution to simply tape off the bridge and mark it as oob

+1 DaveR

Possibly also staff the bridge, to remind people to walk carefully. Perhaps affix yellow hazard tape to the edges of the safe sections.

Stripes, some tape and control to white forest where it is safe making it pointless to go OOB and use (and possible break it more) the unsafe bridge.

Actually, on second thought, I'd suggest don't use it at all. The benefit versus downside sounds all wrong. Certainly, orienteers are used to running through all kinds of stuff in the woods, and sometimes are exposed to sharp rocks or dropoffs. But on manmade features, we have a habit of trusting. How often does one hesitate running (or driving) across a road bridge, despite the hazard if it collapsed, had holes, or was sloped so as to pitch you off? One just assumes that it won't, and trusts one's life to it, probably many times a day unthinkingly. Event and course notes, and signs on controls or bridges, don't always get read or remembered. Staff is limited, and might not get noticed at night especially in a crush.

Can you mark the bridge forbidden, block it using a large obstacle, and streamer orienteers across the gully, perhaps with a control just before and after? Or use the two areas that the route connects for separate events? Or just skip using one part of the area, at least for the night event?

Unfortunately the only facility we can use for the event center is in the small section of the park. The path is the only connection between the two parts. This is a night score style course, so people will pass in both directions. New Year's Day courses of orange, green, and red also will use the corridor in both directions. A short version of the night-O, and the New Year's Day short courses (white, yellow, brown) stay in the small section of the park.

Probably the simplest practical solution is to streamer around it, although any bypass is much more physical than simply taking the 4 or 5 careful steps across the bridge. (it is only 3 meters long, but over a 2+ meter deep gully)

Having the kids build a new bridge between now and the event (one week away) isn't real practical. The erosion problems will quickly wash away any simple light duty bridge, and a permanent bridge needs to be sturdy enough to support service vehicles - its a real engineering job. A permanent solution also requires stabilizing of the gully banks, which are just soft easily-eroded sediment.

Can start and finish be on the same side of the bridge as the large part of the parK? (I.e., a walk to the start/finish?) Or remote start/finish SI units for the longer courses, on that far side of the bridge?

Given attendance numbers on previous New Years Eve Night-Os, I would think pre-start warnings would be sufficient...

Ok, how about a feature that NEOC tried at one of its holiday events...a troll under the bridge, whose riddles one must answer before passing?

Just destroy the bridge, then the onus of liability is gone.

On the South side of the path where it crosses the gully, the forest is white and the erosion gully becomes smaller (changes from solid brown to brown dots). Put a control in this smaller part of the erosion gully. Runners from either direction will slow down approaching the gully, they will thus avoid the bridge by having to make a deviation into the (runnable) forest to visit the control, and will be able to cross the gully safely. If you think it necessary, add streamers into the control from the path in both directions.

If you prepare control descriptions in English, you can add a warning.

If you prepare control descriptions in English, you can add a warning

You can add a warning if in Pictorial (international) as well

I searched the IOF CDs for a specific 'Danger!' symbol Jim, but then I figured IOF would not put one in because they wouldn't want dangerous control sites to be used.

I know you can add a line in the descriptions box, and put text in it - is that what you mean?

Guess you could add the pictorial for manned control and mention the reason for it at the Start.

Who reads control descriptions?

Yes, Warning in text

Looks like IOF has taken away the danger symbol, which used to be an exclamation mark.

I seem to recall a danger symbol in Ski-O but maybe that's changed.

My opinion---I'd make a CAUTION sign and put one on each end of the bridge plus mention it in the meet notes. This does assume that the bridge can be safely crossed if one does use caution. If the bridge is unsafe, than mark it out of bounds and put tape around it.

I've seen the exclamation mark on MTBO maps before too although only on training maps, never in competitions.

So, just curious, what did the organisers end up doing?

Go here

MTBO World Cup maps featuring an exclamation mark within a triangle:
2010 MTBO World Cup - W21E Sprint
2010 MTBO World Cup - M21E Sprint
2010 MTBO World Cup - W21E Middle Distance
2010 MTBO World Cup - M21E Middle Distance

In the MTBO maps, the danger was not immediately obvious from looking at the map. The one in the sprint looks like a trail that ended in forest. No steep dropoff, no terrain-based hazard. In the Middle, the sign looks like it identifies a technical path that ends in either a dead-end or a cliff. (can't tell).

Were they identified in the meet notes?

On the sprint, I don't think that's a short trail dead-ending, I think it's a cliff that's contiguous to a trail bend. The trail is probably really steep, and you could miss the turn and ride off the cliff.

OK. I understand and agree with JJ's interpretation of the map. I didn't see it this way at first; not sure why you'd put (or retain) a cliff on a MTB-O map, except to illustrate possible danger.

In some countries (including Hungary) you are allowed to ride off trail in MTBO so it's necessary to put all features on the map. Even if not, on a standard MTBO map you'd put any feature that aided in navigation (typically only if it's near a track).

I don't see the cliff on the sprint map. Cliffs are 70% black and there's nothing of that nature near the danger symbol. You can see an example near #6 on the M21 sprint map.

tRicky is right, the original interpretation was correct, it's a short trail stub, not a cliff. Must be some unknown danger. Nettles? Broken glass? Dropbears?

MM posed a good question, and it seems provided a reasonable solution.

Calling on MTBO for advice is not helpful, as this discipline does not have its house in order, IMHO.
1. It has a symbol for "dangerous object across tracks or paths, stairs", which is a purple bar at right angles to the track. It "should be used for all obstacles that are difficult to cross".
2. As a result of the second quote from the spec, it is routinely used where a dismount is required but there is no danger (gate with good visibility, for example). It provides route choice information.
3. Clearly something is required for real danger (fallen tree over track round a corner on a fast downhill, for example).
4. Orienteers absorb only a proportion of what is on the map, on a bike probably less than on foot. A purple bar on the map may or may not be seen. An exclamation mark in a triangle ditto, plus in the examples above it isn't clear which bit of terrain it applies to.
5. The inescapable conclusion is that dangerous situations must be marked somehow in the terrain. If they can't be avoided by course planning.

I had always wondered why it was considered a 'dangerous object'. Sure it's dangerous if you ride into it or if it fell on you (tree) but on its own? Gee don't tell WorkSafe about all the 'dangerous' objects on an orienteering map. The sport would be banned.