Can hikers and bikers share successfully on trails? - Part 3

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In part 1 & part 2 of this series, we talked about whether sharing was possible and how speed affected the ability to share.  In part 3, we  will talk about sight lines and how they affect the ability to share a trail.

Humans use sight far more than other our other senses to make determinations.  The old adage that “a picture is worth a thousand words” is happening a million times over in our heads every second.  We make choices on everything from foods to clothes based on how they appear to us.  The same is true with our comfort level as we travel down a trail.  We are bombarded with thousands of visual clues about our surrounding and what they mean.  We don’t even think about most of these, such as our brains mapping out where to put our feet based on the visual data at the extents of our vision.

When we talk about “sightlines” as far as trail sharing, we are talking about much more than the length users can see down the trail.  We are talking about all the visual cues that inform how we process what the trail is like, where it goes and where our fellow trails might be.  All of this has some far-ranging impacts on how sharing functions.

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Same eyeballs, different views

Even though all of us as humans have the same eyeballs, we see the trail radical different if we are hiking or mountain biking it.

First, hikers tend to be more “floaty” in what they look at and tend to have their head on a constant swivel.  The result of this is that the trail they are walking on often takes up a much smaller part of the sight picture in their brains.  Also, as they look around they may be looking away from the trail for significant lengths of time.  Therefore, many hikers describe the experience of being passed by mountain bikers as “being snuck up on” or that mountain bikers “come from nowhere”.  This can be very acute if the trail is a downhill and both hiker and mountain biker are going downhill as the bike will be approaching from the rear of the hiker.

Second, while mountain bikers do tend to look around at the scenery more than hikers might think, the fact is that at certain points on the trail, mountain bikers tend to focus on the trail ahead.  This often occurs on technical uphills and, of course, downhills.  Because of this, when these sections of trail occur, the trail occupies nearly all the mountain biker’s sight picture.  This may explain why mountain biker on mountain biker collisions are relatively rare.  With the trail itself being the focus of the rider, anything on the trail immediately will cause the rider to brake and slow down.  This also explains why there are lower percentages of mountain bikers that find sharing to be problematic compared to hikers.

Edges are a thing

In the previous part of this series, we introduced the idea of “edge friction”, that is the way the trail, especially the extremities of trail, inform our brains on whether it was safe to go faster or slower.  The classic concept of sightlines, that is the length a user can see down the trail, is part of this “edge friction”.  Here the edge is defined by the horizon of the trail, giving an edge of our forward vision.

Long sightlines allow us to feel more comfortable, short sightlines make us more cautious.  Again, we return to our ancestors and their experiences.  Open spaces meant predators could be seen from some distance away, closed spaces meant a jaguar could be behind that bush, waiting to pounce.  This is part of the reasons it’s easy to go fast on a highway and hard to do so on a twisty country road.  It’s also part of why trails with longer straightaways and wide sightlines encourage high speeds by mountain bikes.  If a mountain biker can see the trail and surrounding features for 100 yards in front of them and it appears clear, they likely will keep pushing themselves faster.  The human brain is amazingly capable at calculating location and movement based on experience.  Its why we can steer 600,000 ton cargo ships into a port and land flippin’ spaceships with a watch and our eyeballs.  Pushing speeds on a mountain bike to north of 20 mph when we have the sightlines is easy.

But, there is a strange side effect of shorter sightlines: hikers can get nervous.  Remember, no matter if they are teacher or they are a rocket scientist, in their DNA is the belief every bush hides a jaguar.  Shorten up the sightlines too much and other users, especially mountain bikers, will cause them to be uncomfortable.  From the hiker’s perspective, the other users appear basically out of nowhere.

Choked up

There are two ways to keep the sightlines that makes hikers feel comfortable and keep mountain bikes moving at a speed another user will feel comfortable with: a) lots of edge friction and b) choke points.

Again, when you look at trails east of the Rockies, you see these features occurring naturally.  First, the woodlands of the east coast were basically clear-cut in the 19th century.  All new growth is relative new and new wood growth is denser with more underbrush.  Trails here might have to pass between any number of trees, stumps and other obstructions, creating natural choke points.  Second, with weather conditions that occur more frequently in the east, the trails tend to age faster.  Soil compresses, exposing roots, rocks appear, trees fall, making the trail rougher every year, especially along the edges.  It’s not to say these conditions don’t occur in the western United States, it’s just that they happen differently.  A state like Kentucky might have winters almost as wet as Oregon, spring rains as sudden and powerful as California, early summer winds as strong as west Texas, late summer weeks without rain like Arizona and freezing temps as the leaves fall.  And it will have those conditions every year.
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We need to take a moment to talk about two realities of modern trails: machine building and trail sanitation.  Machine built trail is the fastest way to create large miles of new trail.  However, when constructed, those trails will only be as narrow as the machine that builds them, usually around 42” wide.  On top of this land managers (and unfortunately some mountain bikers) sanitize trails by removing items on or at the edge of the trail, usually in the name of “safety” or “liability”.  This removes edge friction and opens the trail, increasing mountain bike speeds.  For machine built trails, maintaining them is about keeping them draining properly, not making them a museum.  It’s ok to have them age in with rocks and other items slowly becoming more visible.  Regarding trail sanitation, faster mountain bike speeds are more likely to allow riders to be hurt when they have an accident.  Also, smoother trails without edge friction can get users in over their heads much easier, meaning users can be hitting features they have no business even attempting.

Sanitized trail is not only not fun, it turns out to be more dangerous. Don't do this. Ever.

Looking at places where there are not issues with sharing, we see commonalities.  Besides the tighter trail layout, we talked about in part 2 of this series, they often have natural features or create features that balance sightlines while having regular choke points and plenty of edge friction.  Often, these items exist in a way that users, both hikers and mountain bikers, get used to and therefore recreate them when building new trails because that is all they know.  Places like Knoxville, TN don’t have better people than a place like Marin County, CA, they just had a set of circumstances they found worked for them and now replicate them on new trails.  Those people in Knoxville might not even know why it’s easy to share on their trails, they just know it is. 

We now have a few more items to add to our knowledge of sharing:

• Different users see the same trail differently.
• The further forward a mountain biker can see, the faster they will likely go.  
• Lots of edge friction and regular choke points can keep hiker’s preferred sightlines but break up those sightlines for mountain bikers, causing them to go slower.

Therefore, if we want to create trails that are shared between user groups successfully, it means we must think about the sightlines of the user and how different users see the same trail differently.  A hiker might see two trees or rocks on the sides of trail as just part of the trail, but a mountain biker might see a cause for concern and slow down.  Knowing that users have different responses to the way a trail looks will mean we would want to make choices in both design and maintenance to make something comfortable for both sets of users.  When trails are new, we let them age into something rough with lots going on at the edges.  Most importantly, once trails are established, we won’t take away that roughness or reduce the edge friction, i.e. sanitize the trail.

This article is part 3 of a 5 part series about sharing.    Next up: How usage and attitude affect the ability to share.