Our Maps & Ratings
See how we map Effort, Stress, and other features of Paths, Routes, and Trails
Our goal is to generate descriptions to help walkers, hikers, and cyclists identify the option just right for them. Using Digital Elevation Mapping (DEM) wherever feasible (see right), we map the grade of paths and trails every 10' (and routes every 30'), which helps to to establish whether a path meets Universal Access standards. Hikers can also rely on our descriptions (see below) until maps are available.
Interested in the mechanics of our GPS mapping?
We download a GPX file corresponding to the route from Google Maps or All Trails. We generate a text file using GPS Visualizer, which can also add tick points and elevations at 10' or 30' intervals using DEMs. We manually correct DEMs thrown off by bridges and tunnels. Where steep terrain, makes DEM inaccurate, we map elevations on the trail itself using our Garmin GPS Map 65S. A custom spreadsheet assigns grades for each interval and calculates Flat Equivalent Length.
We mapped this shared use loop heading north (counter-clockwise) from the parking lot. You encounter moderate uphill grades almost immediately and then a 50' section of difficult grades. Because uphill grades are less steep going in the other direction, we recommend that those who find steep uphill grades difficult consider walking this loop clockwise.
On Trails - Coming Soon
A modified BLTS
One of the limitations of BLTS is that is was developed and has been used primarily in urban and suburban settings. The BLTS model yet to be adapted to accommodate conditions more often found in rural settings. For sections of the route where we have additional information, we have modified the BLTS model as described below.
Actual prevailing speeds and/or volumes: DVRPC derives their ratings based on assumptions about speed (e.g., posted speed limits) and volume given the type of road, not on actual traffic studies. In rural regions like Kennett, drivers are more likely to speed, and volumes can sometimes be very low. We indicate wherever actual traffic studies change BLTS.
Limited Sight Distance: mmmThis used in some cases where additional information is available regarding the likely presence of sections with limited sight distance (see below) or (these models otherwise use posted speed limits and estimated volumes to model traffic stress).
Every 30' section on the route for which BLTS has been modified is outlined in red..
like sections with limited sight distance (see below).
Limited sight sections
because of the road’s horizontal or vertical curvature, sometimes worsened by shrubs or trees. Drivers may not be able to see far enough ahead to safely pull around cyclists, increasing the risk of accidents.
We used William’s (2021) paper to establish minimum sight distances (i.e., 2 times the stopping sight distance) based on posted speed (or prevailing speed, when these data were available. Because our interest was in perceived stress as well as actual danger, we added 50’ to the minimum sight distance. Whenever a section was suspected, we measured the sight distance and increased the BLTS by 1 point at each 20’ section for which sight distance was an issue.