What If GPS Went Dark for 24 Hours?

At 6:17 a.m., a truck carrying medical oxygen approaches a fork in the road. Its blue dot stops moving. In this hypothetical 24-hour outage of civilian satellite navigation and timing signals, one delivery reveals how roads, airports, ports and networks keep working when they lose a reference they rely on. 00:00 The blue dot 00:51 What went dark 03:39 Dispatch without a fix 06:28 Air and harbor 10:26 When clocks drift 14:05 Night shift 17:29 The signal returns 19:54 The other side