The project concerns the modernization works and putting in 2×2 lanes of the RN4 at the level at the junction with RL 621 from El Fahs to Pk 13,7 through the town of Sidi Aouidet. It originates at Pk 13,70 at the intersection with the RL621 and ends at the level of the governorate limit at Pk 28,2.

This study also includes:

• Study to improve the alignment.
• Studies of the doubling and reconstruction of all the structures and hydraulics of which the most important are located at:
  • Pk 24+200 on Oued El Kebir.
  • Pk 28+200 on oued El Kébir.
• Studies of street lighting at city crossings and crossroads.