Arch Roundabout (commonly referred to as Rainbow RB) will shut starting Thursday, and construction at the junction will continue through 2015, public works authority Ashghal has announced.

Traffic in and around the intersection, a crucial one for West Bay traffic, will instead be rerouted to newly-built roads that connect Omar al-Mukhtar Street with the Lusail Street detour (heading toward Katara and The Pearl), as construction on a new expressway intensifies.

Here is a diagram from Ashghal of the latest construction detours:

The map also offers alternative route suggestions (in blue and red).

Ashghal will have traffic signals installed at two new intersections near Arch Roundabout to facilitate the alternative flow of traffic, and is also making several U-turns available.

In a statement sent out this evening, the public works authority stressed that all possible steps have been taken to minimize traffic disruption:

“Ashghal has been working relentlessly to complete these high quality alternative routes, built to highest technical and design specifications to insure minimal disruption during construction.

All necessary road signs have been installed at all diversions to provide clear directions for commuters. Ashghal has urged all road users to respect traffic rules and regulations for their safety and the safety of others.”

Once the construction is complete, Arch Roundabout will be transformed into a three-level interchange on the Lusail Expressway connecting Dafna and West Bay with the upcoming Lusail development.

Here are pictures from Ashghal of the new detour:

Work officially began last year on the 5.3km highway with no clear deadline for completion announced, before expanding last May to convert the other three roundabouts on Lusail Street into interchanges.

However, SMS and Twitter alerts sent by Ashghal today indicate the project is slated for completion in the second half of 2015.