There were two roads at the time that led from Jerusalem to Gaza. The first one went straight west to the coastal plains via the village of Lydda and linked with the caravan route between Egypt and Damascus. The second extended southward from Jerusalem to Hebron and then westward to Gaza. This (second) route would be the desert road.1
26 Now an angel of the Lord said to Philip, “Rise and go toward the south to the road that goes down from Jerusalem to Gaza.” This is a desert place.