When trails cross

An informational illustration of an Iron Crossing

​Your and your local club are scouting locations for future trails to create in your park.  However, you have a problem.  There is great terrain over here and over there, but between those two areas is a popular regional trail or hiking only trail.  How do you cross said trail and not turn the crossing into a source of concern for yourselves, the land manager and (most importantly) the public?  The answer: an Iron Crossing.

​Why we need a way to make such crossings safe

Before we talk about the specifics of an Iron Crossing, let’s take a moment to understand why, especially for urban trails, we might need some special crossing.

Urban parks and public lands typically are not great tracts of uninterrupted wilderness.  In America, park lands tended to be the “leftovers”, that is, land that couldn’t be built on, farmed or otherwise used (and abused).  This often makes for oddly shaped parks whose borders where established by disinterest in exploitation.  Within these parks, natural features like wetlands and drainageways may isolate areas or render them unsuitable for trails.  Additionally, these parks tend to have paths, trails and accessways crisscrossing what contiguous land there is.  Therefore, as late comers to the game, any new trails created for use by mountain bikers have to fit into existing sections of land.  This often means a sort of “island hopping”, moving from one location of good terrain to another, with the resulting intersections between.

These points of crossing could become a point of conflict if not managed correctly.  In the more wooded parts of the country, especially the logged over woods of the Eastern United States, sightlines within the forest are not long.  Trails usually represent the longest sightlines available, but even then, 30’ may be “long” sightlines in many areas.  It wouldn’t take a rocket scientist to figure out that a mountain biker in such a situation, with little or no sightlines to the sides of a trail, could come upon a crossing with little or no warning.  If that crossing has people on it at the time the mountain biker approaches, unable to see the mountain biker either, the situation is set for a collision.  Even if a collision doesn’t happen, someone is getting the fright of their life.

That moment, where one user is surprised or even frightened is the moment where animosity can be born.  Having enough people finding the sudden appearance of mountain bikers across a trail can cause perception and management issues.  Op-eds filled with embellished accounts of “speeding mountain bikers” or “near misses” are not what we.
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In some ways, Iron Crossings are more a perception control device than a mountain biker control device.  Their purpose is to slow mountain bikers down and narrow the potential crossing point to the smallest conceivable area, changing the perception of the non-mountain biking public.  Perception matters and for urban mountain biking, perception can be the make or break component.

​What is an Iron Crossing?

A construction detail for an Iron Crossing

In its most basic form, an Iron Crossing is a double direction chute, that is two chutes that direct there respective groups along two paths.  In fact, the name “Iron Crossing” is a word play on the idea that when viewed directly from overhead, it resembles an iron cross, technically a cross pattee, used in the German military decoration.  This shape creates a relatively small area for the crossing to happen, thereby limiting the potential for any surprises for parties on either trail.

At the intersection of the two trails an Iron Crossing acts as a choke point.  Choke points slow down users as they pass through them.  For the trail to be used mostly by mountain bikers, let’s call it the “A” trail, the width of the choke point is such that it barely clears mountain bike handlebars.  The reason is simple:  this will cause the mountain bike riders to slow down the maximum amount before the crossing, thereby causing them to cross at a relative slow speed.  As we have discussed before, its speeds, more than any other factor that can make hikers nervous on shared trails.  While in this scenario the trail that is intersecting the mountain bike trail, lets call it the “B” trail, may or may not be shared, the fact is that a slow crossing speed by mountain bikes helps make any persons on the B trail much more comfortable.  Those on B trail get squeezed too, subtly placing them in the mindset of awareness.  Depending on the type of intersecting trail, the squeeze can get pretty narrow for those on that B trail, in its narrowest form, being able to allow one person through at a time.

There is an additional bonus: it is possible to use an iron crossing to prevent mountain bikers on the A trail from turning onto the B trail.  Because of the length and turning radius of mountain bikes, even at a crawl, if the distance between the “arms” of the B trail at the intersection with the A trail are less than 6’, its virtually impossible for a bike to turn onto that trail.  This is useful where the intersecting trail is not approved for use by mountain bikers.

​Iron Crossing construction

What are Iron Crossings made of?  The simplest forms are made with precut cedar split rail fence components.  A 10’ length of these fence sections cost about $45 from big box home improvement retailers like Menards.  Because each section consists of 2 posts and 2 rails, its relatively easy to carry these components into a location where an Iron Crossing is to be constructed.  However, these are not the only options.

Rocks, especially those approximately the size of a washing machine, can also be used.  However, for an Iron Crossing made of rocks to be effective, the rocks cannot be so tall as to block the sight lines of parties on either trail.  Even though an Iron Crossing makes the crossing smaller and more controlled and hence safer, the parties will still need to look for approaching users.  Blocking sightlines lowers the safety of Iron Crossings.

Another option is sectional metal fencing, either steel or aluminum.  These can be purchased at big box home improvement retailers just as the split rail fencing can be.  Metal fencing can have several advantages over wood fencing.  First, and most obviously, they last longer than wood can in most environments.  Second, they are less prone to vandalism.  They can’t be set on fire and short of having a vehicle of some kind, they are hard to rip out.  Third, these types of fences can have gates added to the crossing points extremely easily.  If your trail system closes for weather or other events, if the mountain biking trail crosses another trail, that is an access point that you will need to control.  Gates make this easy.  Fourth, and purely a minor reason, is they can look quite decorative, if not regal.  Also, the aluminum styles tend to come in a variety of colors, everything from bare metal to faux patina.
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One option that is not recommended is the use of vinyl fencing.  Vinyl fencing does have advantages, such as color and decorative options.  However, those are its only advantages.  It’s very prone to vandalism.  Additionally, in certain environments the vinyl gets brittle and even minor bumps against it will cause cracking, if not shattering.  Lastly, there is the microplastics problem.  Vinyl tends to degrade along the edges, becoming a point vector for microplastics being released into the environment.  This is especially true where it cracks due to impact, age or stress.
While we have talked mostly about purchasable options, there are others, such as home-made colonial fences.  Shale or limestone slab fencing might be workable also.  In other parts of the world woven willow or bamboo fencing are options.

​The little things

​Iron Crossings are one of those things that seem rather pointless, maybe even superfluous.  However, they can greatly improve everyone’s experience.  They allow for safer crossings of trails, opening a whole host of routing options.  Where situations of trail crossing are forced upon trail designers by terrain, environmental factors or special factors, Iron Crossings can be the difference between a short trail system and a longer one.  It turns out that Iron Crossings are just one of those little things that can make urban mountain biking possible.