The metropolitan road plan included adding a 5-km extension to Abu Bakr Al-Siddiq Road southward until Salah Al-Din Al-Ayoubi Road, and a 6-km extension to Al-Orouba Road eastward until Abdulrahman Al-Ghafiqi Street, adjacent to the Eastern Ring Road, across the King Salman Airbase (formerly known as Riyadh Airbase).
The rapid growth of Riyadh has witnessed over the recent years overload in metropolitan traffic system and asserted the need for an integrated approach to handle this issue, especially that King Salman Airbase now falls in the heart of the city.
Serving 560,000 vehicles daily, the project is expected to reduce the kilometers driven in the city by 129,000 km per day and the hours spent on the roads by more than 58,000 hours per day.
The two roads have underpasses beneath the King Salman Airbase, which hosts the Royal Hall and runways, in addition to the airbase’s infrastructure and facilities. Therefore, certain operational, security and safety requirements must be met, in addition to compliance with international aviation regulations and standards. The requirements include ensuring operational availability of the base, runways and aviation support services throughout the project.
These considerations were studied by specialized committees designated by Ministry of Defense and Aviation as well as Royal Commission for Riyadh City, which made the following recommendations:
Reconstruction and relocation of all facilities, hangars, runways, communication systems and services that conflict with the course of the roads.
aspects were highlighted through the artistic graffiti drawings, the magnificent design of the square that hosts intersection of Abu Bakr Al Siddiq Road and Oruba Road, the elegant distribution of trees, and design of the lampposts that makes movement on both roads safer.
Design of the two roads considered environment protection requirements. Accordingly, the green areas and esthetical structural elements formed as an important aspect of the design. Moreover, the rocky formationswere retained to add another esthetical dimension to the project.
The project elements were tailored to ensure the highest traffic capacity, create safe environment, and meet the requirements of traffic management, safety, operation, instructional services, and the esthetical and functional lighting.
The main road comprises three 3.6-meter wide tracks in addition to 2.8-meter wide emergency track in each direction, with the possibility of adding a two-track wide frontage road in case of developing the neighboring areas. There are also dedicated tracks for entrances and exits in addition to 3.5-meter central island. Furthermore, a tunnel extending for 955 meters at the intersection of King Abdulaziz Road and Oruba Road was built to allow northern and southern detours at King Abdulaziz Road.
The project included implementation of three tunnels beneath the runways. Each tunnel is 35-meter wide with a total length of 2 km. Two tunnels are connected to the Oruba Road, and the third is connected to Abu Bakr Al-Siddiq Road. Moreover, a new internal underpass was built near the airbase.
A new 750-meter-long overpass with two lanes was also built at the intersection of Al-Orouba Road with the Eastern Ring Road (exit 11) to accommodate the south-west traffic.
The heart of the project hosted Prince Sattam Square, one of Riyadh largest squares with a total area of 330,000 m². The square provides a free intersection for U-turns to all directions and facilitates transition between Abu Bakr Al-Siddiq Road and Oruba Road.
The square has 1256 artistic aircraft patterns, 45 national flags, and 42 beautiful funnels to indicate air directionimparting an attractive visual dimension and modern spirit to the square which blends with its environs and the ambient aviation activities.
The fully roofed tunnels that run beneath runways provide highly streamlined traffic on thecity two main axes. To ensure the tunnels’ efficient function, they were equipped with safety and security equipment including light intensity sensors, vehicle counters, variable-message signs, ventilation equipment, 58 emergency call centers, surveillance cameras, alarm bells, escape gates, and lights across the tunnel’s tracks.
Furthermore, the tunnels are equipped with 132 microphones and a set of instructional signs that indicate locations of passersby escape exits. The tunnels also have access gates for the emergency vehicles, and U-turns before and after each tunnel. Additionally, in case of an emergencyit is possible to communicate with the drivers via their vehicles’ radio sets using 98 and 100 FM frequencies (later all FM frequencies were used).
The tunnels are equipped with 113 ventilation fans that push the air forward along the movement’s direction in each side to accelerate the ventilation process. The airflow direction can be reversed in case of fire to improve efficiency of firefighting activities.
The ventilation fans operate automatically and their speed and direction are controlled via sensors for measuring carbon and nitrogen rates, in addition to heat sensors. All these systems and fittings are controlled and operated remotely from control centers.
Generally, fires are among the main dangers that may occur in the tunnels due to the relatively speedy ignition due to dynamic influence of the flammable gases. Hence, special attention was paid to the firefighting system, which comprises four main components; early warning systems, firefighting fixed and mobile centers, fire extinguishers, and emergency exits.
Lighting the tunnels linking the two roads was implemented innovatively. The tunnels are equipped with about 7000 normal and emergency lighting units. The daily and nightly lighting modes ensure that light intensity is very high at the tunnel ends during the daytime to be consistent with the daylight outside the tunnels as determined by the light intensity sensors that control the light intensity to avoid dazzling the drivers, while at the same time meeting the tunnels’ safety requirements.
The tunnels were also equipped with red and white LED light indicators in two opposite directions to indicate the sides of the roads inside the tunnels, and the courses to be taken by the passersby in cases of emergency.
The tracks of both roads were lit using 330 16-meter high lampposts, while the square was lit using 122 12-meter high lampposts.
The aesthetic aspects form integral part of the project’s design, which included structural elements that created a rich visual, natural and artistic environment without affecting the area’s natural rocky formations.
The project included building 11 km of 3-meter high walls on both sides of the roads. In some parts of the project, 8 km of 5-meter high walls were built around the extensions of the roads inside the airbase. The walls were decorated with paintings and functional signs to indicate directions.
About 1000 palm trees were planted adjacent to the roads and in-between the project’s different elements. About 3000 trees were planted throughout the project, in addition to covering about 45,000 m²with natural grass, and 200,000 m²with the synthetic grass to alleviate the environmental pollution resulting from the vehicles’ carbon monoxide emissions.
The tunnels were equipped with 18 working pumps and 5 reserve ones for rainwater drainage, in addition to irrigation network inside water processing station, with seven giant wirelessly-controlled pumps to irrigate the project green areas. The daily capacity of these pumps amounts to 2800 m³, while the daily capacity of the reservoir is 6000 m³.
The project also has a 10.6-km canal for rainwater drainage starting from the northern diversion channel at the beginning of Prince Sultan Bin Abd El Aziz Street, then heading northward in parallel to Abu Bakr Al-Siddiq Road through King Salman Airbase, until reaching Imam Saud Bin Abd El Aziz Bin Muhammad Road. Furthermore, the project is equipped with networks to drain the underground water and water used in firefighting. Four deep wells were dug and two stations for environmental monitoring were established to provide indicators of rainwater, humidity, and wind speed at the project location.
The project relied on advanced traffic management systems that work harmoniously to achieve the maximum traffic capacity and safety. The main roads are equipped with 22 instructional variable-message signs, 161 functional variable-message signs, 120 signboards controlling the tracks inside the three tunnels, and automatic system for traffic monitoring and counting at the intersections and along the roads using 260 fixed cameras and about 34 axis cameras.
The central control room operates the project’s traffic systems through specialists who instruct the drivers automatically in cases of traffic congestion or accidents, may Allah forbid. The main purpose of this central control room is to achieve the highest levels of traffic smoothness.
On Rabee II 28, 1434H (March 10 , 2013), His Royal Highness Prince Khalid bin Bandar bin Abdulaziz Al Saud opened the extension of Abu Bakr Al-Siddiq and Oruba Street across the King Salman Airbase project. His Highness also opened the tunnel of the intersection between King Abdulaziz Road with Oruba Road.