I heard a story the other day about a man who was trying to drive from Perth to Adelaide across the Nullarbor Plain. He had driven as far as Kalgoorlie (593 km or 370 miles) only to find out the the Eyre Highway across the Nullarbor was blocked because of bushfires. This direct route (at least to Port Augusta) would have been 1153 miles or 1890 kilometres.
He asked Google Maps to find the best alternate route using made (bitumen) roads. He is the detour that he was given.
It meant a distance of 3820 miles or 6265 kilometres. Assuming that he drove all the way at 110 km / hours that would have taken around 60 hours or six days of driving. His original route could have been completed in about two days.
I assume that he sat in Kalgoorlie and waited for the road to be re-opened!