How walk-to-the-train minutes are made
The map answers one question: about how many minutes it takes to walk from this lot to the nearest Metro-North platform. It does not time a specific sidewalk route.
The walking model
Each residential parcel in the New York State tax parcel data has a center point. The station points are the published Metro-North platforms, not the parking lots. We measure the straight-line distance between the two points and multiply it by 1.35, because streets in a suburban grid are not straight. Then we divide by 3 miles per hour. 1.35 is a commonly used detour factor for street networks. We did not measure every block in these towns.
Left out on purpose: hills, traffic signals at crossings, snow, the stairs or ramp at the station, and which side of the tracks the house is on.
Which lots count
Lots with a property class code that starts with 2, New York's residential series. Vacant residential land is included, because the time is for the lot. Commercial and school parcels are left out. A town's median is the median of all those lots.
Ardsley-on-Hudson
The stop named Ardsley-on-Hudson sits in Irvington. Ardsley Village has no Metro-North station. The village median is the walk to Hartsdale or Dobbs Ferry. It is the longest median in these editions, because there is no platform inside the village line.
What this does not cover
This does not give train times, and it is not the "minutes to NYC" a listing quotes. It says nothing about school buses or the Bee-Line. Check the route on a map that shows sidewalks, and the train times on the MTA site.
FAQ
Why not use Google walking directions?
Walking directions would need a live routing request for every lot each time the page loads. The straight-line model gives the same result every time and works the same way in every town. It can be a few minutes off on a winding hill street.
Why 3 mph and 1.35?
3 mph is a steady walk on level ground. 1.35 is a typical extra length for suburban streets compared with a straight line. Changing either one would change every number, so both are fixed to keep towns comparable.
Unofficial. Confirm figures on the town’s official roll or in PROS, the county’s property records system, before you act on them.