I am doing an OD cost matrix where the OD pairs are cities across 11 countries in Central Asia. I am trying to add border delay penalties in minutes to the total travel distance and I believe this will be possible using scaled cost polygon barrier. Border delay/penalty is different in each country. The idea is to add appropriate cost everytime the route traveled touches a border.
Polygon barriers will "slow" down the entire route as they impact all the edges inside the polygon. And if you are applying it to the entire country, there maybe too many edges and performance will not be good. Also, barriers "scale" the cost on the features, not add a fixed cost. The correct way to model a border delay or cost is to identify the border crossing edge and change its cost OR add a Turn feature there with the additional cost or place a junction there with a cost to go through the junction. Just note that junction costs are same regardless which way you cross them, whereas the edge costs can be bi-directional.