Use caution with trail map applications

Navigation applications that have all of the local tracks pre-loaded are one of the newest pieces of hiking technology. An example is a popular app called Gaia GPS.
Unfortunately, these new applications with pre-loaded tracks fail to provide an important piece of information: Which of these lines are hiking trails and which of these lines are mountaineering routes? This shortcoming is not obvious to all users and a number of hikers have gotten themselves into serious trouble by following lines on these maps without doing additional research ahead of time. What follows is not a criticism of OpenStreetMap, the volunteers that contribute to it, or the applications that rely on it. OpenStreetMap provides value today and is improving continuously but it can get people into trouble if they are not aware of its limitations.

Consider this screenshot from Gaia GPS (Update: Some changes have since been made to the naming of this specific trail by search and rescue volunteers to help reduce confusion— see the next section for how that works):

It would not be unreasonable to see how a user that has arrived at the fork may think that Mount Harvey Trail and Mount Harvey North Ramp are two trails that lead down from Mount Harvey. The reality is quite different. The North Ramp is a complex mountaineering route that requires technical equipment (many parties use ropes) and has been the location of more than one search and rescue call.

Many of these applications get their track information from the same source and so the issue is not isolated to a single track or a single application. A bit further north of Mount Harvey, the Strava website shows tracks going up the Northeast Face of Mt. Garibaldi and it also shows the Garibaldi Neve Traverse. These are both mountaineering routes and should definitely not be attempted by anyone who is just out for a hike.

Why does this problem exist?

In both cases, the software applications are using data from OpenStreetMap. You can think of OpenStreetMap as a Wikipedia for map information. Volunteers from around the world can add elements to the maps such as roads, rivers and even buildings. Over time, it is becoming an incredibly powerful dataset. Companies that are building software applications can use that map data without needing to add all of the trails themselves.

Here is a screenshot showing the website that allows anyone in the world to edit the trails in OpenStreetMap. If you want, you can quickly create an account and start making your own contributions.

There are some specific challenges with the data in OpenStreetMap when used in hiking trail applications.

Issue 1: Anyone can add a trail

This is important to know but it is not as risky as it seems. Although anyone can make an account and starting adding new trails, completely false trails are likely to be found and deleted by the community. The crowd is generally effective at this type of quality control.

Issue 2: What is a trail?

This is a bigger challenge. In the OpenStreetMap system, the main way you identify something as a trail is by setting a the value of a tag called highway to be equal to “path.” From the OpenStreetMap wiki:

highway=path is a generic path, either multi-use or unspecified usage, open to all non-motorized vehicles and not intended for motorized vehicles unless tagged so separately. The path may have any type of surface. This includes walking and hiking trails, bike trails and paths, horse and stock trails, mountain bike trails as well as combinations of the above.”

As you can see, that’s a very broad category and there is a very wide range of different trails and routes that you might apply that tag to. There is an additional tag that allows users to provide more information about the difficulty of a hiking trail by assigning it a value from the Swiss Alpine Club (SAC) hiking scale.

The options for the SAC Scale tag are:
T1 Hiking
T2 Mountain hiking 
T3 Challenging hiking
T4 Alpine hiking
T5 Sophisticated alpine hiking
T6 Difficult alpine hiking

You can read more about the SAC scale here:
http://www.alpenwanderleiter.ch/wa_files/Structure_20oft_20the_20SAC_20Trekkingscale.pdf

Source: http://www.alpenwanderleiter.ch/wa_files/Structure_20oft_20the_20SAC_20Trekkingscale.pdf

One challenge with the SAC hiking scale is that it is not broadly used; especially in North America. In the context of OpenStreetMap, an additional challenge is that it is an optional tag and many trails have not been assigned a value.

There is also a tag for trail visibility which has also not been applied consistently. You can read more about this tag (and the other tags) on the OpenStreetMap wiki here:

As a further complication, some routes are classified as a “Piste/Ski Route” instead of as a “Path”. This is an interesting distinction since many routes can be used for hiking, skiing or biking depending on the time of the year and the preference of the user.

Issue 3: How should a trail be named?

Names can also be used to convey important information about a track. For example, you could append all trails with “trail” and all technical routes with “climbing route” or “mountaineering route”. Unfortunately, there is no standard in OpenStreetMap or otherwise for how tracks should be named. In the first example in this article, we looked at how “Mount Harvey Trail” and “Mount Harvey North Ramp” might be confusing when they are shown with the same type of line. The community has since renamed “Mount Harvey North Ramp” to “Mount Harvey North Ramp (climbing route)” to make it more clear that it is not a hiking trail but even that could be confusing due to the lack of a standard for how these routes are named.

Issue 4: How often are the maps updated?

In the case of the Mount Harvey North Ramp track, the change to the name was made in July, 2018, but as-of September, 2018, Gaia GPS is still showing the old name.

Issue 5: How does the application use all of the available information to render what is displayed in the app?

When applications pull information from OpenStreetMap, they have a number of choices about what types of fields they want to pull and how they want them to be displayed. For example, they could choose to ignore all paths that do not have a value set for the SAC score. As another option, they could display trails in different ways depending on the SAC field. Given the inconsistency with which the SAC field is used it’s not surprising that most apps seem to ignore it completely. The result is that everything that is identified as a path (and even as a ski route!) ends up being shown the same way or nearly the same way on the maps; whether they are a stroll in an urban park or the route up Mt. Everest. Additionally, some of these apps do not have a legend to help users understand what the lines might mean.

What should users of these applications do?

Putting it altogether, it’s easy to see how OpenStreetMap has the potential to become the a very powerful catalog of the world’s trails and mountaineering routes. However, it’s also easy to see the risks associated with relying on it too heavily today.

The solution is to do your own research ahead of time. Before setting out, you need to verify that the tracks on the map are valid and you to understand the level of difficulty and the equipment that may be required for those particular tracks. Do not assume that all of the tracks in these hiking applications represent hiking trails.

What about OpenStreetMap and applications that rely on it?

In my opinion, the current classification system for organizing routes in OpenStreetMap is inadequate; especially in North America where the SAC is basically unheard of. Until the right system is in place, it is unlikely that the fields will be filled out consistently. A discussion of how the system can be modified is beyond the scope of this post.

In the meantime, apps can do more to warn users of the limitations of the tracks that are shown on the maps. It is easy for users to assume that the app companies have verified these trails or to assume that they are all “hiking” trails. I would like to see app companies include a legend with a warning that the displayed tracks are user-contributed and range from paved walking trails to technical mountaineering routes.

Happy Hiking,

Steve Jones

stevejoneshikes@gmail.com