Possible Clues:

• A form of network coverage?
• Paved runway
• Takeoff or touchdown site
• Is that how the river rat turns up on the road?
• Surface material of tar and stone
• Surfaced area as for planes to take off and land
• Road surface material of tar and stone
• Wing requires all-round care in negotiating short runway, perhaps
• Touchdown area?
• River creature rising and surfacing