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I'm trying to find an R package to duplicate a specific bit of functionality of the ESRI network analyst: What ArcMap refers to as 'Service Areas'. Related terms include

  • catchment areas
  • isochrones
  • 'reachability' (walkalytics package)
  • network buffers

What I want looks like an isochrone, but rather than measuring the amount of distance covered in a specified unit of time, I want a polygon representing the bounds of all points within 1.25 miles over the street network.

  • Nothing in the open streetmap routing machine (osrm package) meets my needs.
  • Walkalytics isochrone would give me what i need, if I knew what the walking speed was.

Could someone either point me to a package with this functionality, or tell me what the Walkalytics default speed is?

I'd really like to be able to do this in R, rather than having to go back into ArcMap everytime I need to determine the network distance reachable from a given metro station.

  • OSRM (the engine under the osrm package) can return distance iso-lines. Here's the 1km walking distance from my local castle: maps.openrouteservice.org/… (assuming the URL works). Is that what you want? Does the R package not wrap that? – Spacedman Mar 8 at 8:08
  • The R package does not appear to wrap that functionality: cran.r-project.org/web/packages/osrm/osrm.pdf – Mox Mar 10 at 17:07
  • It wouldn't surprise me if the walking distance and walking time are simply linearly related by a single walking speed. Infer that (or ask OSRM what speed they use) and you should be able to use isochrones. – Spacedman Mar 10 at 18:46
  • Indeed! But without a walking rate, I can't convert between the two. As far as I can tell, OSRM only provides the default 'drivetime' profile without creating an instance of my own, something I fear is beyond my skills. – Mox Mar 11 at 23:55
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I'm not aware of an R package that does this in one simple step but some packages that may help are:

dodgr Which can do routing over route networks within R

opentripplanner Can interface with a local or remote version of the Open Trip Planner that can make isochrones

stplanr Which can interface with several different services such as graphhopper

  • What I want is what Spacedman (above) refers to as distance-based iso-lines. Effectively, I want a polygon whose vertices are at maximum distances from a central point, given a certain distance. – Mox Mar 10 at 17:07
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    The perhaps you could use dodgr to get the points a given distance from a point an then use sf::st_convex_hull() on those points – falcs Mar 10 at 17:33
  • A very interesting idea. I just learned about dodgr today, actually. I've seen the convex hull suggested elsewhere, but without something like dodgr, it didn't seem feasible. – Mox Mar 11 at 23:52
  • Any idea how to use dodgr to estimate a distances along all routes? – Mox Mar 12 at 19:31
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The Walkalytics package can be used for this purpose. I contacted its developer (Stephan Heuel) on Twitter (@ping13), and he replied "The walking speed was modeled to be about 4.5 km/h."(Personal Communication, March 11 2019).

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