MileCheckIs there a mile marker layer for CAD software?
Yes. A mile marker layer is a set of points, one per marker, with the route and number on each. The MileCheck milepost dataset has 396,842 of them across all 50 states (November 2, 2026 release), as CSV and GeoJSON. Those formats load into the GIS most CAD maps are built on.
Where your state's markers come from
Most state DOTs publish a milepost layer on their GIS portal. Each one uses its own fields and route names, and some cover only interstates. If your center only covers one state, the DOT layer may be enough. See does my state DOT publish mile marker data.
What the MileCheck file adds
- One layout for every state, with the route written the way it is on the sign.
- A field that says whether each point is a surveyed sign or placed along the route line.
- A full file with each release, with a list of what changed.
Live lookups instead
If your CAD can call a web service, /v1/locate returns a nearby highway and mile marker for a GPS point when one is within a mile. It can return no match, and crossing roads can make the answer ambiguous. Use it as extra location information, not as a verified 911 location or a replacement for your CAD map and procedures.
Getting it
Download the Utah sample to test the layer in your system. For another state or a quote, write to sales@milecheckapp.com.
Mile marker data for all 50 states
396,842 marker positions as CSV and GeoJSON, one layout for every state, with a list of what changed in each release. Download the Utah sample with no form.
Questions, answered
Which file format do I need?
GeoJSON loads straight into most GIS tools. CSV has latitude and longitude columns for tools that import tables.
Does it include direction?
Where the state places a marker on each side of the road, each row has NB, SB, EB or WB.