Hi Mike,
Did some debugging and it looks like the issue is with slight differences in underground tunnel alignments between polyline you’re passing into the API vs OpenStreetMap (which is what the toll calculator’s mapping data is based on).
You can specify manually specify a match accuracy using the "accuracy"
parameter in the JSON payload. For your polyline, 30m seems to work ok:
{
"polyline": "noenE}ayy...",
"accuracy": 30
}