Karachi: The Karachi Metropolitan Corporation (KMC) has finally decided to demolish Drigh Road flyover, an engineering disaster that needed multiple repairs every year since it was built in 1996.
The demolition of this faulty flyover on Sharae Faisal, which takes the traffic coming from the airport towards Gulshan-e-Iqbal, and the construction of a new one depends, however, on the Sindh government’s approval. A PC-1 feasibility report has been prepared but the government has yet to make a decision, said KMC technical services director-general Niaz Soomro.
Soomro did not, however, rule out the possibility that only the deck slab on the current flyover will be repaired like always. He added that the odds were better that it will be scrapped entirely as the construction was already faulty.
Drigh Road flyover has undergone so many repairs in the last 20 years that officials have lost count. The last count in the year 2012 was 22, according to the then director of technical services at KMC, Altaf G Memon. In this year alone, the flyover has been repaired six times, said KMC assistant executive engineer Muhammad Irfan.
Faults in our flyovers
One of the faults in the flyover was the choice of location. This was the only flyover in the city built on the right-most lane, which is a fast-moving track, explained a KMC engineering officer, who requested not to be named. “It is referred to as ‘Right Lane Flyover’,” he said.
According to him, flyovers across the world are built on the left lane. But in the case of Drigh Road flyover, the authorities needed Pakistan Railways’ permission to construct the flyover on the left-most lane, said the officer, adding that the project needed some portion of railway land but the authorities did not allow.
Hence, the contractor —Maqbool Associates — decided to build it on the right lane, which forced the gradient to become 5% when it should not be more than 3%, he explained. There are, however, no issues with its pilling and girder, he said, adding that only the deck slab needed repairs like Jam Sadiq bridge.
The flyover was also not designed to withstand the kind of traffic load that plies on it, said the officer. “Heavy trucks coming from Super Highway have started using this flyover,” he pointed out, adding that the flyover’s deck slabs are not thick enough to bear that much load, due to which frequent holes emerge.
Aftermath of demolition
If the demolition approval comes though, KMC’s Irfan said they will have to give a U-turn on Sharae Faisal before National Highway Authority’s office for the traffic moving towards Rashid Minhas Road. However, he accepted that this additional U-turn and the new flyover will cause traffic jams on Drigh Road.
Soomro accepted that they will need railways’ permission for the new flyover but he said they will look into it after the Sindh government approves.
KMC is also hoping to widen Sharae Faisal towards Star Gate, said Irfan, adding that they have already obtained some land from Central Ordinance Depot (COD) for this purpose.
The COD’s boundary wall will be shifted inwards before and after Natha Khan Bridge and the road will be widened by 11 metres, he said, adding that a U-turn will be made under Natha Khan bridge, over the rain drain.
Accountability: Who’s to blame?
If a new flyover is being built after demolishing an old one, someone should be held responsible for the faulty construction of the old one, said traffic engineer Ashar Lodhi.
He added that a flyover’s design life is supposed to last 50 years. Nowhere in the world will there be a flyover on the fast-track lane, he said, explaining how that is an engineering disaster. On Drigh Road flyover, public buses that have to go towards Rashid Minhas Road will have to move to the right lane when they should only be using the left lane, he pointed out. Cars, which are usually on the right track and are heading straight towards Metropole, will, however, have to switch to the left lane. This weaving conflict is what leads to road accidents, he said.
Instead of building a new flyover at this spot, Lodhi suggested building one from Rashid Minhas Road towards Sharae Faisal.
