The Haaretz daily said the army decided on the step because existing Gaza roads are too narrow to accommodate the heavy military traffic the evacuation effort is expected to generate.
There was no immediate comment from the army on the report.
Haaretz said new dirt roads will run parallel to three existing thoroughfares connecting Jewish settlement blocs in northern, central and southern Gaza to communities in southern Israel.
It said the army has constructed fences along one of the proposed roads to prevent resistance groups from attacking military and civilian traffic at the time of the evacuation.
The Gaza withdrawal, set for July, intends to evacuate all 8500 Jewish settlers from 21 communities.
Earlier this week a senior Israeli officer said more than 10,000 troops will be trained to carry out the mission. Large numbers of police officers are also expected to participate.