We are using SQL Server to calculate mileage breakdowns per state. It's a simple query to find length of intersection between path (polyline) and shape.
Data for US, MX, and CA were sourced from different public places. Now we got first issue where we see MX and US borders overlap like shown on image:
As you see shapes of TX and MX overlap. Now, this route happens to be in overlapped area and we get double mileage figures.
We need better data. Is there single source where we can obtain all 3 countries with no overlapping data/shapes?