Building a regional trail inventory

Phases of trails

Phase I: Easy trails to establish a hiker's baseline

Our first goal is to map out trails that can help hikers establish their baseline: how far can a new hiker comfortably cover in at least 30 minutes, but preferably 60 minutes.  To control for as many factors as possible, you need flat trails that are paved or have a hardened hardened surface.  You should aim to identify at least 3-5 such trails, to give hikers some choice.  If you have more than 5 possible trails, list your favorites separately (as I did in the Kennett Square inventory).

Some other tips...

• I prefer loops that runs through a shaded forest preserve by a  stream.  A shaded trail can be enjoyed all year round (and may be the only trail you will enjoy on a sunny summer day), and trails by streams tend to be flat - like the Struble Trail.
• List trails in municipal parks separately, as these tend to be overused (I made an exception for the Brandywine Park Loop because the river views are great!).
• At this point, you must avoid any trails with any appreciable slope or steep sections.  For trails listed in Alltrails, you should be careful of any trail with a total elevation gain of more than 100 feet per mile.  Plotting elevation changes using the excel spreadsheet described below is, however, the only way to really be sure.
• You are unlikely to find interesting, flat, paved loops less than 1 1/2 miles in length, and so will likely have to identify good sections with longer trails.  In this case, take care to identify where to start (as we did with the Brandywine Park Loop and the Struble Trail.)
• For now, just note the length of the trail in miles (if doing a section of a longer trail, just note "up to")
• Whenever possible, offer guidance about parking... Is there a parking or entrance fee? Are there alternate parking areas? Do the lots tend to get crowded?

Phase II: Trails for beginners that gradually increase in difficulty

The first step in this next phase is easy: review paved trails identified in the last step and identify those that allow for longer hikes.  For the second (and all subsequent) steps, however, you will have to calculate the effort required for each hike.   This includes a lot of technical stuff described later in this page... downloading existing GPX data into an excel sheet to calculate slope, and so on.

The effort score is key, as it allows hikers and their partners to feel confident that a new hike will be not be markedly more difficult than a familiar hike.  The second step in Phase II requires that you identify paved trails or sections that are up to 2 miles long and that include with a sloped section (i.e., usually more than a 100' elevation change per mile).

The final step in Phase II requires that you identify wide trails, with a stable and even natural surface, up to 2 miles long.  Determining the width and surface of the trail takes additional work.  You may be able to make a reasonable guess through some detective work on specific trail listings in Alltrails.

• Alltrails MapLayersClick the Map Layers (to the right), change to satellite view.  Mowed trails that stay within an open field or  meadow, and that do not include sections that are most difficult, are good candidates. Most parks and preserves do mow trails regularly, and this plus normal traffic all but ensures a good surface, but you can also check the description and photos (next)
• Read the description, and check out the reviews and photos. Look for evidence of muddy or uneven sections.  This might be enough to confirm that even a forested trail is wide enough. A trail that is at least 3 feet wide will give hikers an easy option to step around roots, rocks and some muddy sections, though this only works for hikers who do not need  a partner directly beside them for guidance or support.

If you do not feel confident in the information you are getting from Alltrails, then you may need to make your own maps by walking the trail yourself.

Phase III: Trails for more adventurous hikers

Coming soon!!

Longer and larger trail systems

Longer trails - break into sections

Coming soon!!

Working with ScribbleMaps

 

Customizing a local guide

 

Other technical stuff

Organizing your data

An Alltrails list created using filters is certainly a start, but these filters do not include all of the variables needed to assemble a trail inventory. For that, you need a spreadsheet like Excel, and a regional trail coordinator who comfortable working  with it.

The first spreadsheet is easy: it simply helps to organize your trails by broad categories to identify which trails to look at more closely.  Begin with trails that are rated as easy, and that have a paved or hardened surface.  Include a link back to the original Alltrails listing, as you may need to scan the description to see what the surface is (although that too can be unclear).

​Even though I am very familiar with local trails, I found this list to be helpful in  reminding me of trails I should consider.  It also allows me to add trails that are not in Alltrails - in fact, 20-30% of my favorite trails were not listed. At this point, I like to also note the type of trail: whether it is a forest, or meadow, or mixed, and whether it is a loop.  I also note if this is in a city park. I find that city parks tend to be more crowded, while a forested loop in a nature preserve is likely to be more peaceful and interesting.

Downloading data into Excel

Coming soon!

Calculating Slope: Other Details

Calculating slope from existing GPX data is tricky. Measuring changes in slope from 1 data point to another can magnify errors inherent to GPX data, so we used several techniques to smooth these.  For example, we calculate changes in elevation over overlapping 1o0' sections.  Elevation changes over a half-mile cannot simply be calculated by measuring elevation at the beginning and the end. For example, a downhill section can mask a steep - and more difficult - uphill section. So we calculated average slope only using increases in elevation across overlapping 100'sections, and only for half-mile segments with at least 1/3 of 100' segments that are either flat or positive in slope.

The next step  is more complicated: it involves importing GPX data into a purpose-built Excel spreadsheet to automatically calculate changes in slope and assign effort ratings to each 100 foot section and 1/2 mile segment.  This is important: while an amateur to differentiate a flat from a steep section of trail, they cannot make more subtle distinctions. Is this just a steeper section, or a change in overall slope for an entire 1/2 mile segment?  For hikers like Margot, subtle changes in slope across an half-mile, or more significant changes for a section, can make the difference between a comfortable and an uncomfortable hike. Whether I download an existing GPX file or a trail that I recorded myself from Alltrails into Excel, it takes about 15 minutes to align these data to generate the effort scores for a trail.