Qatar’s public works authority Ashghal is looking for companies to give one of the country’s busiest highways a high-tech overhaul.
The changes include placing variable speed limits on February 22nd Street, the name for part of the expressway which runs between D-Ring and Al-Shamal roads, that can be adjusted according to traffic conditions to improve safety, according to an Ashghal tender document for an “intelligent transportation system” operator.
While few details are included in the document, variable speed limits are used in other jurisdictions, such as Washington State in the US, to let motorists know of congestion up ahead that may require a change in speed.
The objective is to prevent motorists from being forced to slam on their brakes as they come up behind congestion. Instead, encouraging drivers to slow down creates a more consistent traffic flow and reduces the risk of rear-end collisions, according to the Texas A&M Transportation Institute in the US:
Variable speed limits help reduce congestion by encouraging motorists to all drive at a consistent speed, a traffic consultant told Doha News.
“There’s no point in having everyone rush to join the queue,” he said. “Everyone moves continuously.”
Congestion has steadily grown on the expressway since it opened to traffic in 2010 and is regularly the scene of serious collisions.
Over the last year, local traffic officials have tinkered with the speed limit signage on the Doha expressway, starting with an unannounced overnight change from 100 km/h to 80 km/h in January.
At the time, a Traffic Department official was quoted as saying the change was a trial to see if slower speeds would ease congestion and reduce the number of collisions on the road.
Despite claiming that the number of crashes had decreased, traffic department officials said in early August that the speed limit signage would be restored to 100 km/h. However, signs still show the limit at 80 km/h.
The Texas A&M report said traffic authorities need to properly communicate how the system works and its purpose, in order to encourage motorists to comply:
“Drivers must be able to understand why the speed limit is being reduced and that the reason is legitimate.”
Ashghal’s requirements for would-be contractors include technology that enables variable speed limits to be enforced.
The Ministry of Interior has recently extended its use of radar cameras to catch speeders and motorists who pass on the right, which has coincided with a record number of radar-related offences recorded by authorities.
Intelligent transportation systems (ITS) broadly refer to the use of data collected from vehicles, roads and intersections to more efficiently manage the flow of traffic.
Currently, some 70 intersections across the country are equipped with “smart” traffic lights that use sensors to judge the volume of traffic on the roads at any given moment and alter the phasing of the red and green lights accordingly.
Traffic Department officials were quoted as saying in August that all intersections in Qatar would be equipped with the technology, but gave no timeline for the upgrade.
Authorities have said ITS will be a part of all future transportation projects.
“No project will go for tender unless there is ITS infrastructure on it,” Yousef Al Emadi, Ashghal’s manager of roads operations and maintenance, recently told The Edge magazine.
Other components of the February 22nd Street project include:
- Automatic incident detection: Technology identify, locate and clear debris and vehicles involved in collisions from the road using CCTV cameras, vehicle detectors and software;
- Hard-shoulder technology: Enable the use of the hard-shoulder to improve traffic flow during incidents;
- Vehicle type restrictions: Technology to enforce removal of slow-moving, large vehicles during the period of high-volume traffic by using digital signage to instruct commercial vehicles to take alternative routes;
- Traffic signal timing improvements and ramp meters: Technology to improve the movement of traffic on and off February 22 Street;
- Roadway infrastructure protection: Technology to detect and re-route overly tall or heavy vehicles that would otherwise damage infrastructure; and
- Electronic emergency gates: Devices in the center median that can be raised by police to divert traffic onto the opposite lanes during serious incidents.
Ashghal is restricting the February 22nd Street project to Qatari companies and joint ventures. Contractors have until Dec. 8 to respond.
Once a contract is awarded, construction is expected to be completed within 300 days.