I've a Brazil road layer that include start km and end km for each road, some are empties. Have checked and some of the values are wrong so I'll calculate road length by myself. I use ArcGis, but can use any other (Qgis, postgresql-postgis).
Original data is in SIRGAS_2000 GCS_SIRGAS_2000 WKID: 4674 Authority: EPSG
Also have available: SIRGAS_2000_Brazil_Mercator WKID: 5641 Authority: EPSG
What's Best Brazil wide reference system to compute road length?