Ann: First Two Smeltering Furnaces Shipped to Kupang, page-18

I think you will find that the road is tarred all the way now.
If you take the road from the Port of Tenau out to Bolok and then continue along that road to the concrete batching plant and past the adjacent ex-KPR processing plant site and then turn left and head south for about 1km to the GMC site. All on bitumen and about 9.6km.
I think your photo is of the north-south road between the concrete batching plant and the ex-KPR site.